// Algorithm implementation -*- C++ -*- // Copyright (C) 2001-2021 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // . /* * * Copyright (c) 1994 * Hewlett-Packard Company * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Hewlett-Packard Company makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * * * Copyright (c) 1996 * Silicon Graphics Computer Systems, Inc. * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Silicon Graphics makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. */ /** @file bits/stl_algo.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{algorithm} */ #ifndef _STL_ALGO_H #define _STL_ALGO_H 1 #include // for rand #include #include #include // for _Temporary_buffer #include #if __cplusplus >= 201103L #include #endif // See concept_check.h for the __glibcxx_*_requires macros. namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /// Swaps the median value of *__a, *__b and *__c under __comp to *__result template _GLIBCXX20_CONSTEXPR void __move_median_to_first(_Iterator __result,_Iterator __a, _Iterator __b, _Iterator __c, _Compare __comp) { if (__comp(__a, __b)) { if (__comp(__b, __c)) std::iter_swap(__result, __b); else if (__comp(__a, __c)) std::iter_swap(__result, __c); else std::iter_swap(__result, __a); } else if (__comp(__a, __c)) std::iter_swap(__result, __a); else if (__comp(__b, __c)) std::iter_swap(__result, __c); else std::iter_swap(__result, __b); } /// Provided for stable_partition to use. template _GLIBCXX20_CONSTEXPR inline _InputIterator __find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred) { return std::__find_if(__first, __last, __gnu_cxx::__ops::__negate(__pred), std::__iterator_category(__first)); } /// Like find_if_not(), but uses and updates a count of the /// remaining range length instead of comparing against an end /// iterator. template _GLIBCXX20_CONSTEXPR _InputIterator __find_if_not_n(_InputIterator __first, _Distance& __len, _Predicate __pred) { for (; __len; --__len, (void) ++__first) if (!__pred(__first)) break; return __first; } // set_difference // set_intersection // set_symmetric_difference // set_union // for_each // find // find_if // find_first_of // adjacent_find // count // count_if // search template _GLIBCXX20_CONSTEXPR _ForwardIterator1 __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __predicate) { // Test for empty ranges if (__first1 == __last1 || __first2 == __last2) return __first1; // Test for a pattern of length 1. _ForwardIterator2 __p1(__first2); if (++__p1 == __last2) return std::__find_if(__first1, __last1, __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2)); // General case. _ForwardIterator1 __current = __first1; for (;;) { __first1 = std::__find_if(__first1, __last1, __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2)); if (__first1 == __last1) return __last1; _ForwardIterator2 __p = __p1; __current = __first1; if (++__current == __last1) return __last1; while (__predicate(__current, __p)) { if (++__p == __last2) return __first1; if (++__current == __last1) return __last1; } ++__first1; } return __first1; } // search_n /** * This is an helper function for search_n overloaded for forward iterators. */ template _GLIBCXX20_CONSTEXPR _ForwardIterator __search_n_aux(_ForwardIterator __first, _ForwardIterator __last, _Integer __count, _UnaryPredicate __unary_pred, std::forward_iterator_tag) { __first = std::__find_if(__first, __last, __unary_pred); while (__first != __last) { typename iterator_traits<_ForwardIterator>::difference_type __n = __count; _ForwardIterator __i = __first; ++__i; while (__i != __last && __n != 1 && __unary_pred(__i)) { ++__i; --__n; } if (__n == 1) return __first; if (__i == __last) return __last; __first = std::__find_if(++__i, __last, __unary_pred); } return __last; } /** * This is an helper function for search_n overloaded for random access * iterators. */ template _GLIBCXX20_CONSTEXPR _RandomAccessIter __search_n_aux(_RandomAccessIter __first, _RandomAccessIter __last, _Integer __count, _UnaryPredicate __unary_pred, std::random_access_iterator_tag) { typedef typename std::iterator_traits<_RandomAccessIter>::difference_type _DistanceType; _DistanceType __tailSize = __last - __first; _DistanceType __remainder = __count; while (__remainder <= __tailSize) // the main loop... { __first += __remainder; __tailSize -= __remainder; // __first here is always pointing to one past the last element of // next possible match. _RandomAccessIter __backTrack = __first; while (__unary_pred(--__backTrack)) { if (--__remainder == 0) return (__first - __count); // Success } __remainder = __count + 1 - (__first - __backTrack); } return __last; // Failure } template _GLIBCXX20_CONSTEXPR _ForwardIterator __search_n(_ForwardIterator __first, _ForwardIterator __last, _Integer __count, _UnaryPredicate __unary_pred) { if (__count <= 0) return __first; if (__count == 1) return std::__find_if(__first, __last, __unary_pred); return std::__search_n_aux(__first, __last, __count, __unary_pred, std::__iterator_category(__first)); } // find_end for forward iterators. template _GLIBCXX20_CONSTEXPR _ForwardIterator1 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2, forward_iterator_tag, forward_iterator_tag, _BinaryPredicate __comp) { if (__first2 == __last2) return __last1; _ForwardIterator1 __result = __last1; while (1) { _ForwardIterator1 __new_result = std::__search(__first1, __last1, __first2, __last2, __comp); if (__new_result == __last1) return __result; else { __result = __new_result; __first1 = __new_result; ++__first1; } } } // find_end for bidirectional iterators (much faster). template _GLIBCXX20_CONSTEXPR _BidirectionalIterator1 __find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1, _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, bidirectional_iterator_tag, bidirectional_iterator_tag, _BinaryPredicate __comp) { // concept requirements __glibcxx_function_requires(_BidirectionalIteratorConcept< _BidirectionalIterator1>) __glibcxx_function_requires(_BidirectionalIteratorConcept< _BidirectionalIterator2>) typedef reverse_iterator<_BidirectionalIterator1> _RevIterator1; typedef reverse_iterator<_BidirectionalIterator2> _RevIterator2; _RevIterator1 __rlast1(__first1); _RevIterator2 __rlast2(__first2); _RevIterator1 __rresult = std::__search(_RevIterator1(__last1), __rlast1, _RevIterator2(__last2), __rlast2, __comp); if (__rresult == __rlast1) return __last1; else { _BidirectionalIterator1 __result = __rresult.base(); std::advance(__result, -std::distance(__first2, __last2)); return __result; } } /** * @brief Find last matching subsequence in a sequence. * @ingroup non_mutating_algorithms * @param __first1 Start of range to search. * @param __last1 End of range to search. * @param __first2 Start of sequence to match. * @param __last2 End of sequence to match. * @return The last iterator @c i in the range * @p [__first1,__last1-(__last2-__first2)) such that @c *(i+N) == * @p *(__first2+N) for each @c N in the range @p * [0,__last2-__first2), or @p __last1 if no such iterator exists. * * Searches the range @p [__first1,__last1) for a sub-sequence that * compares equal value-by-value with the sequence given by @p * [__first2,__last2) and returns an iterator to the __first * element of the sub-sequence, or @p __last1 if the sub-sequence * is not found. The sub-sequence will be the last such * subsequence contained in [__first1,__last1). * * Because the sub-sequence must lie completely within the range @p * [__first1,__last1) it must start at a position less than @p * __last1-(__last2-__first2) where @p __last2-__first2 is the * length of the sub-sequence. This means that the returned * iterator @c i will be in the range @p * [__first1,__last1-(__last2-__first2)) */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator1 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>) __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_ForwardIterator1>::value_type, typename iterator_traits<_ForwardIterator2>::value_type>) __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); return std::__find_end(__first1, __last1, __first2, __last2, std::__iterator_category(__first1), std::__iterator_category(__first2), __gnu_cxx::__ops::__iter_equal_to_iter()); } /** * @brief Find last matching subsequence in a sequence using a predicate. * @ingroup non_mutating_algorithms * @param __first1 Start of range to search. * @param __last1 End of range to search. * @param __first2 Start of sequence to match. * @param __last2 End of sequence to match. * @param __comp The predicate to use. * @return The last iterator @c i in the range @p * [__first1,__last1-(__last2-__first2)) such that @c * predicate(*(i+N), @p (__first2+N)) is true for each @c N in the * range @p [0,__last2-__first2), or @p __last1 if no such iterator * exists. * * Searches the range @p [__first1,__last1) for a sub-sequence that * compares equal value-by-value with the sequence given by @p * [__first2,__last2) using comp as a predicate and returns an * iterator to the first element of the sub-sequence, or @p __last1 * if the sub-sequence is not found. The sub-sequence will be the * last such subsequence contained in [__first,__last1). * * Because the sub-sequence must lie completely within the range @p * [__first1,__last1) it must start at a position less than @p * __last1-(__last2-__first2) where @p __last2-__first2 is the * length of the sub-sequence. This means that the returned * iterator @c i will be in the range @p * [__first1,__last1-(__last2-__first2)) */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator1 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>) __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>) __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator1>::value_type, typename iterator_traits<_ForwardIterator2>::value_type>) __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); return std::__find_end(__first1, __last1, __first2, __last2, std::__iterator_category(__first1), std::__iterator_category(__first2), __gnu_cxx::__ops::__iter_comp_iter(__comp)); } #if __cplusplus >= 201103L /** * @brief Checks that a predicate is true for all the elements * of a sequence. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __pred A predicate. * @return True if the check is true, false otherwise. * * Returns true if @p __pred is true for each element in the range * @p [__first,__last), and false otherwise. */ template _GLIBCXX20_CONSTEXPR inline bool all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) { return __last == std::find_if_not(__first, __last, __pred); } /** * @brief Checks that a predicate is false for all the elements * of a sequence. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __pred A predicate. * @return True if the check is true, false otherwise. * * Returns true if @p __pred is false for each element in the range * @p [__first,__last), and false otherwise. */ template _GLIBCXX20_CONSTEXPR inline bool none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) { return __last == _GLIBCXX_STD_A::find_if(__first, __last, __pred); } /** * @brief Checks that a predicate is true for at least one element * of a sequence. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __pred A predicate. * @return True if the check is true, false otherwise. * * Returns true if an element exists in the range @p * [__first,__last) such that @p __pred is true, and false * otherwise. */ template _GLIBCXX20_CONSTEXPR inline bool any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) { return !std::none_of(__first, __last, __pred); } /** * @brief Find the first element in a sequence for which a * predicate is false. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __pred A predicate. * @return The first iterator @c i in the range @p [__first,__last) * such that @p __pred(*i) is false, or @p __last if no such iterator exists. */ template _GLIBCXX20_CONSTEXPR inline _InputIterator find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__find_if_not(__first, __last, __gnu_cxx::__ops::__pred_iter(__pred)); } /** * @brief Checks whether the sequence is partitioned. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __pred A predicate. * @return True if the range @p [__first,__last) is partioned by @p __pred, * i.e. if all elements that satisfy @p __pred appear before those that * do not. */ template _GLIBCXX20_CONSTEXPR inline bool is_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred) { __first = std::find_if_not(__first, __last, __pred); if (__first == __last) return true; ++__first; return std::none_of(__first, __last, __pred); } /** * @brief Find the partition point of a partitioned range. * @ingroup mutating_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __pred A predicate. * @return An iterator @p mid such that @p all_of(__first, mid, __pred) * and @p none_of(mid, __last, __pred) are both true. */ template _GLIBCXX20_CONSTEXPR _ForwardIterator partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_ForwardIterator>::value_type>) // A specific debug-mode test will be necessary... __glibcxx_requires_valid_range(__first, __last); typedef typename iterator_traits<_ForwardIterator>::difference_type _DistanceType; _DistanceType __len = std::distance(__first, __last); while (__len > 0) { _DistanceType __half = __len >> 1; _ForwardIterator __middle = __first; std::advance(__middle, __half); if (__pred(*__middle)) { __first = __middle; ++__first; __len = __len - __half - 1; } else __len = __half; } return __first; } #endif template _GLIBCXX20_CONSTEXPR _OutputIterator __remove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred) { for (; __first != __last; ++__first) if (!__pred(__first)) { *__result = *__first; ++__result; } return __result; } /** * @brief Copy a sequence, removing elements of a given value. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @param __value The value to be removed. * @return An iterator designating the end of the resulting sequence. * * Copies each element in the range @p [__first,__last) not equal * to @p __value to the range beginning at @p __result. * remove_copy() is stable, so the relative order of elements that * are copied is unchanged. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator remove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_InputIterator>::value_type, _Tp>) __glibcxx_requires_valid_range(__first, __last); return std::__remove_copy_if(__first, __last, __result, __gnu_cxx::__ops::__iter_equals_val(__value)); } /** * @brief Copy a sequence, removing elements for which a predicate is true. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @param __pred A predicate. * @return An iterator designating the end of the resulting sequence. * * Copies each element in the range @p [__first,__last) for which * @p __pred returns false to the range beginning at @p __result. * * remove_copy_if() is stable, so the relative order of elements that are * copied is unchanged. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator remove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__remove_copy_if(__first, __last, __result, __gnu_cxx::__ops::__pred_iter(__pred)); } #if __cplusplus >= 201103L /** * @brief Copy the elements of a sequence for which a predicate is true. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @param __pred A predicate. * @return An iterator designating the end of the resulting sequence. * * Copies each element in the range @p [__first,__last) for which * @p __pred returns true to the range beginning at @p __result. * * copy_if() is stable, so the relative order of elements that are * copied is unchanged. */ template _GLIBCXX20_CONSTEXPR _OutputIterator copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); for (; __first != __last; ++__first) if (__pred(*__first)) { *__result = *__first; ++__result; } return __result; } template _GLIBCXX20_CONSTEXPR _OutputIterator __copy_n(_InputIterator __first, _Size __n, _OutputIterator __result, input_iterator_tag) { return std::__niter_wrap(__result, __copy_n_a(__first, __n, std::__niter_base(__result), true)); } template _GLIBCXX20_CONSTEXPR inline _OutputIterator __copy_n(_RandomAccessIterator __first, _Size __n, _OutputIterator __result, random_access_iterator_tag) { return std::copy(__first, __first + __n, __result); } /** * @brief Copies the range [first,first+n) into [result,result+n). * @ingroup mutating_algorithms * @param __first An input iterator. * @param __n The number of elements to copy. * @param __result An output iterator. * @return result+n. * * This inline function will boil down to a call to @c memmove whenever * possible. Failing that, if random access iterators are passed, then the * loop count will be known (and therefore a candidate for compiler * optimizations such as unrolling). */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator copy_n(_InputIterator __first, _Size __n, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) const auto __n2 = std::__size_to_integer(__n); if (__n2 <= 0) return __result; __glibcxx_requires_can_increment(__first, __n2); __glibcxx_requires_can_increment(__result, __n2); return std::__copy_n(__first, __n2, __result, std::__iterator_category(__first)); } /** * @brief Copy the elements of a sequence to separate output sequences * depending on the truth value of a predicate. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __out_true An output iterator. * @param __out_false An output iterator. * @param __pred A predicate. * @return A pair designating the ends of the resulting sequences. * * Copies each element in the range @p [__first,__last) for which * @p __pred returns true to the range beginning at @p out_true * and each element for which @p __pred returns false to @p __out_false. */ template _GLIBCXX20_CONSTEXPR pair<_OutputIterator1, _OutputIterator2> partition_copy(_InputIterator __first, _InputIterator __last, _OutputIterator1 __out_true, _OutputIterator2 __out_false, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator1, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator2, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); for (; __first != __last; ++__first) if (__pred(*__first)) { *__out_true = *__first; ++__out_true; } else { *__out_false = *__first; ++__out_false; } return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false); } #endif // C++11 template _GLIBCXX20_CONSTEXPR _ForwardIterator __remove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) { __first = std::__find_if(__first, __last, __pred); if (__first == __last) return __first; _ForwardIterator __result = __first; ++__first; for (; __first != __last; ++__first) if (!__pred(__first)) { *__result = _GLIBCXX_MOVE(*__first); ++__result; } return __result; } /** * @brief Remove elements from a sequence. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __value The value to be removed. * @return An iterator designating the end of the resulting sequence. * * All elements equal to @p __value are removed from the range * @p [__first,__last). * * remove() is stable, so the relative order of elements that are * not removed is unchanged. * * Elements between the end of the resulting sequence and @p __last * are still present, but their value is unspecified. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator remove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_ForwardIterator>::value_type, _Tp>) __glibcxx_requires_valid_range(__first, __last); return std::__remove_if(__first, __last, __gnu_cxx::__ops::__iter_equals_val(__value)); } /** * @brief Remove elements from a sequence using a predicate. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __pred A predicate. * @return An iterator designating the end of the resulting sequence. * * All elements for which @p __pred returns true are removed from the range * @p [__first,__last). * * remove_if() is stable, so the relative order of elements that are * not removed is unchanged. * * Elements between the end of the resulting sequence and @p __last * are still present, but their value is unspecified. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator remove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__remove_if(__first, __last, __gnu_cxx::__ops::__pred_iter(__pred)); } template _GLIBCXX20_CONSTEXPR _ForwardIterator __adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __binary_pred) { if (__first == __last) return __last; _ForwardIterator __next = __first; while (++__next != __last) { if (__binary_pred(__first, __next)) return __first; __first = __next; } return __last; } template _GLIBCXX20_CONSTEXPR _ForwardIterator __unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __binary_pred) { // Skip the beginning, if already unique. __first = std::__adjacent_find(__first, __last, __binary_pred); if (__first == __last) return __last; // Do the real copy work. _ForwardIterator __dest = __first; ++__first; while (++__first != __last) if (!__binary_pred(__dest, __first)) *++__dest = _GLIBCXX_MOVE(*__first); return ++__dest; } /** * @brief Remove consecutive duplicate values from a sequence. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @return An iterator designating the end of the resulting sequence. * * Removes all but the first element from each group of consecutive * values that compare equal. * unique() is stable, so the relative order of elements that are * not removed is unchanged. * Elements between the end of the resulting sequence and @p __last * are still present, but their value is unspecified. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator unique(_ForwardIterator __first, _ForwardIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_EqualityComparableConcept< typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__unique(__first, __last, __gnu_cxx::__ops::__iter_equal_to_iter()); } /** * @brief Remove consecutive values from a sequence using a predicate. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __binary_pred A binary predicate. * @return An iterator designating the end of the resulting sequence. * * Removes all but the first element from each group of consecutive * values for which @p __binary_pred returns true. * unique() is stable, so the relative order of elements that are * not removed is unchanged. * Elements between the end of the resulting sequence and @p __last * are still present, but their value is unspecified. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __binary_pred) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__unique(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__binary_pred)); } /** * This is an uglified * unique_copy(_InputIterator, _InputIterator, _OutputIterator, * _BinaryPredicate) * overloaded for forward iterators and output iterator as result. */ template _GLIBCXX20_CONSTEXPR _OutputIterator __unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __binary_pred, forward_iterator_tag, output_iterator_tag) { // concept requirements -- iterators already checked __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) _ForwardIterator __next = __first; *__result = *__first; while (++__next != __last) if (!__binary_pred(__first, __next)) { __first = __next; *++__result = *__first; } return ++__result; } /** * This is an uglified * unique_copy(_InputIterator, _InputIterator, _OutputIterator, * _BinaryPredicate) * overloaded for input iterators and output iterator as result. */ template _GLIBCXX20_CONSTEXPR _OutputIterator __unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __binary_pred, input_iterator_tag, output_iterator_tag) { // concept requirements -- iterators already checked __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_InputIterator>::value_type, typename iterator_traits<_InputIterator>::value_type>) typename iterator_traits<_InputIterator>::value_type __value = *__first; __decltype(__gnu_cxx::__ops::__iter_comp_val(__binary_pred)) __rebound_pred = __gnu_cxx::__ops::__iter_comp_val(__binary_pred); *__result = __value; while (++__first != __last) if (!__rebound_pred(__first, __value)) { __value = *__first; *++__result = __value; } return ++__result; } /** * This is an uglified * unique_copy(_InputIterator, _InputIterator, _OutputIterator, * _BinaryPredicate) * overloaded for input iterators and forward iterator as result. */ template _GLIBCXX20_CONSTEXPR _ForwardIterator __unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __binary_pred, input_iterator_tag, forward_iterator_tag) { // concept requirements -- iterators already checked __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_InputIterator>::value_type>) *__result = *__first; while (++__first != __last) if (!__binary_pred(__result, __first)) *++__result = *__first; return ++__result; } /** * This is an uglified reverse(_BidirectionalIterator, * _BidirectionalIterator) * overloaded for bidirectional iterators. */ template _GLIBCXX20_CONSTEXPR void __reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag) { while (true) if (__first == __last || __first == --__last) return; else { std::iter_swap(__first, __last); ++__first; } } /** * This is an uglified reverse(_BidirectionalIterator, * _BidirectionalIterator) * overloaded for random access iterators. */ template _GLIBCXX20_CONSTEXPR void __reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag) { if (__first == __last) return; --__last; while (__first < __last) { std::iter_swap(__first, __last); ++__first; --__last; } } /** * @brief Reverse a sequence. * @ingroup mutating_algorithms * @param __first A bidirectional iterator. * @param __last A bidirectional iterator. * @return reverse() returns no value. * * Reverses the order of the elements in the range @p [__first,__last), * so that the first element becomes the last etc. * For every @c i such that @p 0<=i<=(__last-__first)/2), @p reverse() * swaps @p *(__first+i) and @p *(__last-(i+1)) */ template _GLIBCXX20_CONSTEXPR inline void reverse(_BidirectionalIterator __first, _BidirectionalIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_requires_valid_range(__first, __last); std::__reverse(__first, __last, std::__iterator_category(__first)); } /** * @brief Copy a sequence, reversing its elements. * @ingroup mutating_algorithms * @param __first A bidirectional iterator. * @param __last A bidirectional iterator. * @param __result An output iterator. * @return An iterator designating the end of the resulting sequence. * * Copies the elements in the range @p [__first,__last) to the * range @p [__result,__result+(__last-__first)) such that the * order of the elements is reversed. For every @c i such that @p * 0<=i<=(__last-__first), @p reverse_copy() performs the * assignment @p *(__result+(__last-__first)-1-i) = *(__first+i). * The ranges @p [__first,__last) and @p * [__result,__result+(__last-__first)) must not overlap. */ template _GLIBCXX20_CONSTEXPR _OutputIterator reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_BidirectionalIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); while (__first != __last) { --__last; *__result = *__last; ++__result; } return __result; } /** * This is a helper function for the rotate algorithm specialized on RAIs. * It returns the greatest common divisor of two integer values. */ template _GLIBCXX20_CONSTEXPR _EuclideanRingElement __gcd(_EuclideanRingElement __m, _EuclideanRingElement __n) { while (__n != 0) { _EuclideanRingElement __t = __m % __n; __m = __n; __n = __t; } return __m; } inline namespace _V2 { /// This is a helper function for the rotate algorithm. template _GLIBCXX20_CONSTEXPR _ForwardIterator __rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, forward_iterator_tag) { if (__first == __middle) return __last; else if (__last == __middle) return __first; _ForwardIterator __first2 = __middle; do { std::iter_swap(__first, __first2); ++__first; ++__first2; if (__first == __middle) __middle = __first2; } while (__first2 != __last); _ForwardIterator __ret = __first; __first2 = __middle; while (__first2 != __last) { std::iter_swap(__first, __first2); ++__first; ++__first2; if (__first == __middle) __middle = __first2; else if (__first2 == __last) __first2 = __middle; } return __ret; } /// This is a helper function for the rotate algorithm. template _GLIBCXX20_CONSTEXPR _BidirectionalIterator __rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last, bidirectional_iterator_tag) { // concept requirements __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept< _BidirectionalIterator>) if (__first == __middle) return __last; else if (__last == __middle) return __first; std::__reverse(__first, __middle, bidirectional_iterator_tag()); std::__reverse(__middle, __last, bidirectional_iterator_tag()); while (__first != __middle && __middle != __last) { std::iter_swap(__first, --__last); ++__first; } if (__first == __middle) { std::__reverse(__middle, __last, bidirectional_iterator_tag()); return __last; } else { std::__reverse(__first, __middle, bidirectional_iterator_tag()); return __first; } } /// This is a helper function for the rotate algorithm. template _GLIBCXX20_CONSTEXPR _RandomAccessIterator __rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last, random_access_iterator_tag) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) if (__first == __middle) return __last; else if (__last == __middle) return __first; typedef typename iterator_traits<_RandomAccessIterator>::difference_type _Distance; typedef typename iterator_traits<_RandomAccessIterator>::value_type _ValueType; _Distance __n = __last - __first; _Distance __k = __middle - __first; if (__k == __n - __k) { std::swap_ranges(__first, __middle, __middle); return __middle; } _RandomAccessIterator __p = __first; _RandomAccessIterator __ret = __first + (__last - __middle); for (;;) { if (__k < __n - __k) { if (__is_pod(_ValueType) && __k == 1) { _ValueType __t = _GLIBCXX_MOVE(*__p); _GLIBCXX_MOVE3(__p + 1, __p + __n, __p); *(__p + __n - 1) = _GLIBCXX_MOVE(__t); return __ret; } _RandomAccessIterator __q = __p + __k; for (_Distance __i = 0; __i < __n - __k; ++ __i) { std::iter_swap(__p, __q); ++__p; ++__q; } __n %= __k; if (__n == 0) return __ret; std::swap(__n, __k); __k = __n - __k; } else { __k = __n - __k; if (__is_pod(_ValueType) && __k == 1) { _ValueType __t = _GLIBCXX_MOVE(*(__p + __n - 1)); _GLIBCXX_MOVE_BACKWARD3(__p, __p + __n - 1, __p + __n); *__p = _GLIBCXX_MOVE(__t); return __ret; } _RandomAccessIterator __q = __p + __n; __p = __q - __k; for (_Distance __i = 0; __i < __n - __k; ++ __i) { --__p; --__q; std::iter_swap(__p, __q); } __n %= __k; if (__n == 0) return __ret; std::swap(__n, __k); } } } // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 488. rotate throws away useful information /** * @brief Rotate the elements of a sequence. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __middle A forward iterator. * @param __last A forward iterator. * @return first + (last - middle). * * Rotates the elements of the range @p [__first,__last) by * @p (__middle - __first) positions so that the element at @p __middle * is moved to @p __first, the element at @p __middle+1 is moved to * @p __first+1 and so on for each element in the range * @p [__first,__last). * * This effectively swaps the ranges @p [__first,__middle) and * @p [__middle,__last). * * Performs * @p *(__first+(n+(__last-__middle))%(__last-__first))=*(__first+n) * for each @p n in the range @p [0,__last-__first). */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_requires_valid_range(__first, __middle); __glibcxx_requires_valid_range(__middle, __last); return std::__rotate(__first, __middle, __last, std::__iterator_category(__first)); } } // namespace _V2 /** * @brief Copy a sequence, rotating its elements. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __middle A forward iterator. * @param __last A forward iterator. * @param __result An output iterator. * @return An iterator designating the end of the resulting sequence. * * Copies the elements of the range @p [__first,__last) to the * range beginning at @result, rotating the copied elements by * @p (__middle-__first) positions so that the element at @p __middle * is moved to @p __result, the element at @p __middle+1 is moved * to @p __result+1 and so on for each element in the range @p * [__first,__last). * * Performs * @p *(__result+(n+(__last-__middle))%(__last-__first))=*(__first+n) * for each @p n in the range @p [0,__last-__first). */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator rotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __middle); __glibcxx_requires_valid_range(__middle, __last); return std::copy(__first, __middle, std::copy(__middle, __last, __result)); } /// This is a helper function... template _GLIBCXX20_CONSTEXPR _ForwardIterator __partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag) { if (__first == __last) return __first; while (__pred(*__first)) if (++__first == __last) return __first; _ForwardIterator __next = __first; while (++__next != __last) if (__pred(*__next)) { std::iter_swap(__first, __next); ++__first; } return __first; } /// This is a helper function... template _GLIBCXX20_CONSTEXPR _BidirectionalIterator __partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred, bidirectional_iterator_tag) { while (true) { while (true) if (__first == __last) return __first; else if (__pred(*__first)) ++__first; else break; --__last; while (true) if (__first == __last) return __first; else if (!bool(__pred(*__last))) --__last; else break; std::iter_swap(__first, __last); ++__first; } } // partition /// This is a helper function... /// Requires __first != __last and !__pred(__first) /// and __len == distance(__first, __last). /// /// !__pred(__first) allows us to guarantee that we don't /// move-assign an element onto itself. template _ForwardIterator __stable_partition_adaptive(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, _Distance __len, _Pointer __buffer, _Distance __buffer_size) { if (__len == 1) return __first; if (__len <= __buffer_size) { _ForwardIterator __result1 = __first; _Pointer __result2 = __buffer; // The precondition guarantees that !__pred(__first), so // move that element to the buffer before starting the loop. // This ensures that we only call __pred once per element. *__result2 = _GLIBCXX_MOVE(*__first); ++__result2; ++__first; for (; __first != __last; ++__first) if (__pred(__first)) { *__result1 = _GLIBCXX_MOVE(*__first); ++__result1; } else { *__result2 = _GLIBCXX_MOVE(*__first); ++__result2; } _GLIBCXX_MOVE3(__buffer, __result2, __result1); return __result1; } _ForwardIterator __middle = __first; std::advance(__middle, __len / 2); _ForwardIterator __left_split = std::__stable_partition_adaptive(__first, __middle, __pred, __len / 2, __buffer, __buffer_size); // Advance past true-predicate values to satisfy this // function's preconditions. _Distance __right_len = __len - __len / 2; _ForwardIterator __right_split = std::__find_if_not_n(__middle, __right_len, __pred); if (__right_len) __right_split = std::__stable_partition_adaptive(__right_split, __last, __pred, __right_len, __buffer, __buffer_size); return std::rotate(__left_split, __middle, __right_split); } template _ForwardIterator __stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) { __first = std::__find_if_not(__first, __last, __pred); if (__first == __last) return __first; typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType; typedef typename iterator_traits<_ForwardIterator>::difference_type _DistanceType; _Temporary_buffer<_ForwardIterator, _ValueType> __buf(__first, std::distance(__first, __last)); return std::__stable_partition_adaptive(__first, __last, __pred, _DistanceType(__buf.requested_size()), __buf.begin(), _DistanceType(__buf.size())); } /** * @brief Move elements for which a predicate is true to the beginning * of a sequence, preserving relative ordering. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __pred A predicate functor. * @return An iterator @p middle such that @p __pred(i) is true for each * iterator @p i in the range @p [first,middle) and false for each @p i * in the range @p [middle,last). * * Performs the same function as @p partition() with the additional * guarantee that the relative ordering of elements in each group is * preserved, so any two elements @p x and @p y in the range * @p [__first,__last) such that @p __pred(x)==__pred(y) will have the same * relative ordering after calling @p stable_partition(). */ template inline _ForwardIterator stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__stable_partition(__first, __last, __gnu_cxx::__ops::__pred_iter(__pred)); } /// This is a helper function for the sort routines. template _GLIBCXX20_CONSTEXPR void __heap_select(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last, _Compare __comp) { std::__make_heap(__first, __middle, __comp); for (_RandomAccessIterator __i = __middle; __i < __last; ++__i) if (__comp(__i, __first)) std::__pop_heap(__first, __middle, __i, __comp); } // partial_sort template _GLIBCXX20_CONSTEXPR _RandomAccessIterator __partial_sort_copy(_InputIterator __first, _InputIterator __last, _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp) { typedef typename iterator_traits<_InputIterator>::value_type _InputValueType; typedef iterator_traits<_RandomAccessIterator> _RItTraits; typedef typename _RItTraits::difference_type _DistanceType; if (__result_first == __result_last) return __result_last; _RandomAccessIterator __result_real_last = __result_first; while (__first != __last && __result_real_last != __result_last) { *__result_real_last = *__first; ++__result_real_last; ++__first; } std::__make_heap(__result_first, __result_real_last, __comp); while (__first != __last) { if (__comp(__first, __result_first)) std::__adjust_heap(__result_first, _DistanceType(0), _DistanceType(__result_real_last - __result_first), _InputValueType(*__first), __comp); ++__first; } std::__sort_heap(__result_first, __result_real_last, __comp); return __result_real_last; } /** * @brief Copy the smallest elements of a sequence. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __result_first A random-access iterator. * @param __result_last Another random-access iterator. * @return An iterator indicating the end of the resulting sequence. * * Copies and sorts the smallest N values from the range @p [__first,__last) * to the range beginning at @p __result_first, where the number of * elements to be copied, @p N, is the smaller of @p (__last-__first) and * @p (__result_last-__result_first). * After the sort if @e i and @e j are iterators in the range * @p [__result_first,__result_first+N) such that i precedes j then * *j<*i is false. * The value returned is @p __result_first+N. */ template _GLIBCXX20_CONSTEXPR inline _RandomAccessIterator partial_sort_copy(_InputIterator __first, _InputIterator __last, _RandomAccessIterator __result_first, _RandomAccessIterator __result_last) { #ifdef _GLIBCXX_CONCEPT_CHECKS typedef typename iterator_traits<_InputIterator>::value_type _InputValueType; typedef typename iterator_traits<_RandomAccessIterator>::value_type _OutputValueType; #endif // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_ConvertibleConcept<_InputValueType, _OutputValueType>) __glibcxx_function_requires(_LessThanOpConcept<_InputValueType, _OutputValueType>) __glibcxx_function_requires(_LessThanComparableConcept<_OutputValueType>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); __glibcxx_requires_valid_range(__result_first, __result_last); return std::__partial_sort_copy(__first, __last, __result_first, __result_last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Copy the smallest elements of a sequence using a predicate for * comparison. * @ingroup sorting_algorithms * @param __first An input iterator. * @param __last Another input iterator. * @param __result_first A random-access iterator. * @param __result_last Another random-access iterator. * @param __comp A comparison functor. * @return An iterator indicating the end of the resulting sequence. * * Copies and sorts the smallest N values from the range @p [__first,__last) * to the range beginning at @p result_first, where the number of * elements to be copied, @p N, is the smaller of @p (__last-__first) and * @p (__result_last-__result_first). * After the sort if @e i and @e j are iterators in the range * @p [__result_first,__result_first+N) such that i precedes j then * @p __comp(*j,*i) is false. * The value returned is @p __result_first+N. */ template _GLIBCXX20_CONSTEXPR inline _RandomAccessIterator partial_sort_copy(_InputIterator __first, _InputIterator __last, _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp) { #ifdef _GLIBCXX_CONCEPT_CHECKS typedef typename iterator_traits<_InputIterator>::value_type _InputValueType; typedef typename iterator_traits<_RandomAccessIterator>::value_type _OutputValueType; #endif // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_ConvertibleConcept<_InputValueType, _OutputValueType>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _InputValueType, _OutputValueType>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _OutputValueType, _OutputValueType>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); __glibcxx_requires_valid_range(__result_first, __result_last); return std::__partial_sort_copy(__first, __last, __result_first, __result_last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } /// This is a helper function for the sort routine. template _GLIBCXX20_CONSTEXPR void __unguarded_linear_insert(_RandomAccessIterator __last, _Compare __comp) { typename iterator_traits<_RandomAccessIterator>::value_type __val = _GLIBCXX_MOVE(*__last); _RandomAccessIterator __next = __last; --__next; while (__comp(__val, __next)) { *__last = _GLIBCXX_MOVE(*__next); __last = __next; --__next; } *__last = _GLIBCXX_MOVE(__val); } /// This is a helper function for the sort routine. template _GLIBCXX20_CONSTEXPR void __insertion_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { if (__first == __last) return; for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i) { if (__comp(__i, __first)) { typename iterator_traits<_RandomAccessIterator>::value_type __val = _GLIBCXX_MOVE(*__i); _GLIBCXX_MOVE_BACKWARD3(__first, __i, __i + 1); *__first = _GLIBCXX_MOVE(__val); } else std::__unguarded_linear_insert(__i, __gnu_cxx::__ops::__val_comp_iter(__comp)); } } /// This is a helper function for the sort routine. template _GLIBCXX20_CONSTEXPR inline void __unguarded_insertion_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { for (_RandomAccessIterator __i = __first; __i != __last; ++__i) std::__unguarded_linear_insert(__i, __gnu_cxx::__ops::__val_comp_iter(__comp)); } /** * @doctodo * This controls some aspect of the sort routines. */ enum { _S_threshold = 16 }; /// This is a helper function for the sort routine. template _GLIBCXX20_CONSTEXPR void __final_insertion_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { if (__last - __first > int(_S_threshold)) { std::__insertion_sort(__first, __first + int(_S_threshold), __comp); std::__unguarded_insertion_sort(__first + int(_S_threshold), __last, __comp); } else std::__insertion_sort(__first, __last, __comp); } /// This is a helper function... template _GLIBCXX20_CONSTEXPR _RandomAccessIterator __unguarded_partition(_RandomAccessIterator __first, _RandomAccessIterator __last, _RandomAccessIterator __pivot, _Compare __comp) { while (true) { while (__comp(__first, __pivot)) ++__first; --__last; while (__comp(__pivot, __last)) --__last; if (!(__first < __last)) return __first; std::iter_swap(__first, __last); ++__first; } } /// This is a helper function... template _GLIBCXX20_CONSTEXPR inline _RandomAccessIterator __unguarded_partition_pivot(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { _RandomAccessIterator __mid = __first + (__last - __first) / 2; std::__move_median_to_first(__first, __first + 1, __mid, __last - 1, __comp); return std::__unguarded_partition(__first + 1, __last, __first, __comp); } template _GLIBCXX20_CONSTEXPR inline void __partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last, _Compare __comp) { std::__heap_select(__first, __middle, __last, __comp); std::__sort_heap(__first, __middle, __comp); } /// This is a helper function for the sort routine. template _GLIBCXX20_CONSTEXPR void __introsort_loop(_RandomAccessIterator __first, _RandomAccessIterator __last, _Size __depth_limit, _Compare __comp) { while (__last - __first > int(_S_threshold)) { if (__depth_limit == 0) { std::__partial_sort(__first, __last, __last, __comp); return; } --__depth_limit; _RandomAccessIterator __cut = std::__unguarded_partition_pivot(__first, __last, __comp); std::__introsort_loop(__cut, __last, __depth_limit, __comp); __last = __cut; } } // sort template _GLIBCXX20_CONSTEXPR inline void __sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { if (__first != __last) { std::__introsort_loop(__first, __last, std::__lg(__last - __first) * 2, __comp); std::__final_insertion_sort(__first, __last, __comp); } } template _GLIBCXX20_CONSTEXPR void __introselect(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Size __depth_limit, _Compare __comp) { while (__last - __first > 3) { if (__depth_limit == 0) { std::__heap_select(__first, __nth + 1, __last, __comp); // Place the nth largest element in its final position. std::iter_swap(__first, __nth); return; } --__depth_limit; _RandomAccessIterator __cut = std::__unguarded_partition_pivot(__first, __last, __comp); if (__cut <= __nth) __first = __cut; else __last = __cut; } std::__insertion_sort(__first, __last, __comp); } // nth_element // lower_bound moved to stl_algobase.h /** * @brief Finds the first position in which @p __val could be inserted * without changing the ordering. * @ingroup binary_search_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __val The search term. * @param __comp A functor to use for comparisons. * @return An iterator pointing to the first element not less * than @p __val, or end() if every element is less * than @p __val. * @ingroup binary_search_algorithms * * The comparison function should have the same effects on ordering as * the function used for the initial sort. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_ForwardIterator>::value_type, _Tp>) __glibcxx_requires_partitioned_lower_pred(__first, __last, __val, __comp); return std::__lower_bound(__first, __last, __val, __gnu_cxx::__ops::__iter_comp_val(__comp)); } template _GLIBCXX20_CONSTEXPR _ForwardIterator __upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val, _Compare __comp) { typedef typename iterator_traits<_ForwardIterator>::difference_type _DistanceType; _DistanceType __len = std::distance(__first, __last); while (__len > 0) { _DistanceType __half = __len >> 1; _ForwardIterator __middle = __first; std::advance(__middle, __half); if (__comp(__val, __middle)) __len = __half; else { __first = __middle; ++__first; __len = __len - __half - 1; } } return __first; } /** * @brief Finds the last position in which @p __val could be inserted * without changing the ordering. * @ingroup binary_search_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __val The search term. * @return An iterator pointing to the first element greater than @p __val, * or end() if no elements are greater than @p __val. * @ingroup binary_search_algorithms */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_LessThanOpConcept< _Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_partitioned_upper(__first, __last, __val); return std::__upper_bound(__first, __last, __val, __gnu_cxx::__ops::__val_less_iter()); } /** * @brief Finds the last position in which @p __val could be inserted * without changing the ordering. * @ingroup binary_search_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __val The search term. * @param __comp A functor to use for comparisons. * @return An iterator pointing to the first element greater than @p __val, * or end() if no elements are greater than @p __val. * @ingroup binary_search_algorithms * * The comparison function should have the same effects on ordering as * the function used for the initial sort. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_partitioned_upper_pred(__first, __last, __val, __comp); return std::__upper_bound(__first, __last, __val, __gnu_cxx::__ops::__val_comp_iter(__comp)); } template _GLIBCXX20_CONSTEXPR pair<_ForwardIterator, _ForwardIterator> __equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val, _CompareItTp __comp_it_val, _CompareTpIt __comp_val_it) { typedef typename iterator_traits<_ForwardIterator>::difference_type _DistanceType; _DistanceType __len = std::distance(__first, __last); while (__len > 0) { _DistanceType __half = __len >> 1; _ForwardIterator __middle = __first; std::advance(__middle, __half); if (__comp_it_val(__middle, __val)) { __first = __middle; ++__first; __len = __len - __half - 1; } else if (__comp_val_it(__val, __middle)) __len = __half; else { _ForwardIterator __left = std::__lower_bound(__first, __middle, __val, __comp_it_val); std::advance(__first, __len); _ForwardIterator __right = std::__upper_bound(++__middle, __first, __val, __comp_val_it); return pair<_ForwardIterator, _ForwardIterator>(__left, __right); } } return pair<_ForwardIterator, _ForwardIterator>(__first, __first); } /** * @brief Finds the largest subrange in which @p __val could be inserted * at any place in it without changing the ordering. * @ingroup binary_search_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __val The search term. * @return An pair of iterators defining the subrange. * @ingroup binary_search_algorithms * * This is equivalent to * @code * std::make_pair(lower_bound(__first, __last, __val), * upper_bound(__first, __last, __val)) * @endcode * but does not actually call those functions. */ template _GLIBCXX20_CONSTEXPR inline pair<_ForwardIterator, _ForwardIterator> equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_ForwardIterator>::value_type, _Tp>) __glibcxx_function_requires(_LessThanOpConcept< _Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_partitioned_lower(__first, __last, __val); __glibcxx_requires_partitioned_upper(__first, __last, __val); return std::__equal_range(__first, __last, __val, __gnu_cxx::__ops::__iter_less_val(), __gnu_cxx::__ops::__val_less_iter()); } /** * @brief Finds the largest subrange in which @p __val could be inserted * at any place in it without changing the ordering. * @param __first An iterator. * @param __last Another iterator. * @param __val The search term. * @param __comp A functor to use for comparisons. * @return An pair of iterators defining the subrange. * @ingroup binary_search_algorithms * * This is equivalent to * @code * std::make_pair(lower_bound(__first, __last, __val, __comp), * upper_bound(__first, __last, __val, __comp)) * @endcode * but does not actually call those functions. */ template _GLIBCXX20_CONSTEXPR inline pair<_ForwardIterator, _ForwardIterator> equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_ForwardIterator>::value_type, _Tp>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_partitioned_lower_pred(__first, __last, __val, __comp); __glibcxx_requires_partitioned_upper_pred(__first, __last, __val, __comp); return std::__equal_range(__first, __last, __val, __gnu_cxx::__ops::__iter_comp_val(__comp), __gnu_cxx::__ops::__val_comp_iter(__comp)); } /** * @brief Determines whether an element exists in a range. * @ingroup binary_search_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __val The search term. * @return True if @p __val (or its equivalent) is in [@p * __first,@p __last ]. * * Note that this does not actually return an iterator to @p __val. For * that, use std::find or a container's specialized find member functions. */ template _GLIBCXX20_CONSTEXPR bool binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_LessThanOpConcept< _Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_partitioned_lower(__first, __last, __val); __glibcxx_requires_partitioned_upper(__first, __last, __val); _ForwardIterator __i = std::__lower_bound(__first, __last, __val, __gnu_cxx::__ops::__iter_less_val()); return __i != __last && !(__val < *__i); } /** * @brief Determines whether an element exists in a range. * @ingroup binary_search_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __val The search term. * @param __comp A functor to use for comparisons. * @return True if @p __val (or its equivalent) is in @p [__first,__last]. * * Note that this does not actually return an iterator to @p __val. For * that, use std::find or a container's specialized find member functions. * * The comparison function should have the same effects on ordering as * the function used for the initial sort. */ template _GLIBCXX20_CONSTEXPR bool binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __val, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, _Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_partitioned_lower_pred(__first, __last, __val, __comp); __glibcxx_requires_partitioned_upper_pred(__first, __last, __val, __comp); _ForwardIterator __i = std::__lower_bound(__first, __last, __val, __gnu_cxx::__ops::__iter_comp_val(__comp)); return __i != __last && !bool(__comp(__val, *__i)); } // merge /// This is a helper function for the __merge_adaptive routines. template void __move_merge_adaptive(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) { if (__comp(__first2, __first1)) { *__result = _GLIBCXX_MOVE(*__first2); ++__first2; } else { *__result = _GLIBCXX_MOVE(*__first1); ++__first1; } ++__result; } if (__first1 != __last1) _GLIBCXX_MOVE3(__first1, __last1, __result); } /// This is a helper function for the __merge_adaptive routines. template void __move_merge_adaptive_backward(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1, _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BidirectionalIterator3 __result, _Compare __comp) { if (__first1 == __last1) { _GLIBCXX_MOVE_BACKWARD3(__first2, __last2, __result); return; } else if (__first2 == __last2) return; --__last1; --__last2; while (true) { if (__comp(__last2, __last1)) { *--__result = _GLIBCXX_MOVE(*__last1); if (__first1 == __last1) { _GLIBCXX_MOVE_BACKWARD3(__first2, ++__last2, __result); return; } --__last1; } else { *--__result = _GLIBCXX_MOVE(*__last2); if (__first2 == __last2) return; --__last2; } } } /// This is a helper function for the merge routines. template _BidirectionalIterator1 __rotate_adaptive(_BidirectionalIterator1 __first, _BidirectionalIterator1 __middle, _BidirectionalIterator1 __last, _Distance __len1, _Distance __len2, _BidirectionalIterator2 __buffer, _Distance __buffer_size) { _BidirectionalIterator2 __buffer_end; if (__len1 > __len2 && __len2 <= __buffer_size) { if (__len2) { __buffer_end = _GLIBCXX_MOVE3(__middle, __last, __buffer); _GLIBCXX_MOVE_BACKWARD3(__first, __middle, __last); return _GLIBCXX_MOVE3(__buffer, __buffer_end, __first); } else return __first; } else if (__len1 <= __buffer_size) { if (__len1) { __buffer_end = _GLIBCXX_MOVE3(__first, __middle, __buffer); _GLIBCXX_MOVE3(__middle, __last, __first); return _GLIBCXX_MOVE_BACKWARD3(__buffer, __buffer_end, __last); } else return __last; } else return std::rotate(__first, __middle, __last); } /// This is a helper function for the merge routines. template void __merge_adaptive(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last, _Distance __len1, _Distance __len2, _Pointer __buffer, _Distance __buffer_size, _Compare __comp) { if (__len1 <= __len2 && __len1 <= __buffer_size) { _Pointer __buffer_end = _GLIBCXX_MOVE3(__first, __middle, __buffer); std::__move_merge_adaptive(__buffer, __buffer_end, __middle, __last, __first, __comp); } else if (__len2 <= __buffer_size) { _Pointer __buffer_end = _GLIBCXX_MOVE3(__middle, __last, __buffer); std::__move_merge_adaptive_backward(__first, __middle, __buffer, __buffer_end, __last, __comp); } else { _BidirectionalIterator __first_cut = __first; _BidirectionalIterator __second_cut = __middle; _Distance __len11 = 0; _Distance __len22 = 0; if (__len1 > __len2) { __len11 = __len1 / 2; std::advance(__first_cut, __len11); __second_cut = std::__lower_bound(__middle, __last, *__first_cut, __gnu_cxx::__ops::__iter_comp_val(__comp)); __len22 = std::distance(__middle, __second_cut); } else { __len22 = __len2 / 2; std::advance(__second_cut, __len22); __first_cut = std::__upper_bound(__first, __middle, *__second_cut, __gnu_cxx::__ops::__val_comp_iter(__comp)); __len11 = std::distance(__first, __first_cut); } _BidirectionalIterator __new_middle = std::__rotate_adaptive(__first_cut, __middle, __second_cut, __len1 - __len11, __len22, __buffer, __buffer_size); std::__merge_adaptive(__first, __first_cut, __new_middle, __len11, __len22, __buffer, __buffer_size, __comp); std::__merge_adaptive(__new_middle, __second_cut, __last, __len1 - __len11, __len2 - __len22, __buffer, __buffer_size, __comp); } } /// This is a helper function for the merge routines. template void __merge_without_buffer(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last, _Distance __len1, _Distance __len2, _Compare __comp) { if (__len1 == 0 || __len2 == 0) return; if (__len1 + __len2 == 2) { if (__comp(__middle, __first)) std::iter_swap(__first, __middle); return; } _BidirectionalIterator __first_cut = __first; _BidirectionalIterator __second_cut = __middle; _Distance __len11 = 0; _Distance __len22 = 0; if (__len1 > __len2) { __len11 = __len1 / 2; std::advance(__first_cut, __len11); __second_cut = std::__lower_bound(__middle, __last, *__first_cut, __gnu_cxx::__ops::__iter_comp_val(__comp)); __len22 = std::distance(__middle, __second_cut); } else { __len22 = __len2 / 2; std::advance(__second_cut, __len22); __first_cut = std::__upper_bound(__first, __middle, *__second_cut, __gnu_cxx::__ops::__val_comp_iter(__comp)); __len11 = std::distance(__first, __first_cut); } _BidirectionalIterator __new_middle = std::rotate(__first_cut, __middle, __second_cut); std::__merge_without_buffer(__first, __first_cut, __new_middle, __len11, __len22, __comp); std::__merge_without_buffer(__new_middle, __second_cut, __last, __len1 - __len11, __len2 - __len22, __comp); } template void __inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last, _Compare __comp) { typedef typename iterator_traits<_BidirectionalIterator>::value_type _ValueType; typedef typename iterator_traits<_BidirectionalIterator>::difference_type _DistanceType; typedef _Temporary_buffer<_BidirectionalIterator, _ValueType> _TmpBuf; if (__first == __middle || __middle == __last) return; const _DistanceType __len1 = std::distance(__first, __middle); const _DistanceType __len2 = std::distance(__middle, __last); // __merge_adaptive will use a buffer for the smaller of // [first,middle) and [middle,last). _TmpBuf __buf(__first, std::min(__len1, __len2)); if (__buf.begin() == 0) std::__merge_without_buffer (__first, __middle, __last, __len1, __len2, __comp); else std::__merge_adaptive (__first, __middle, __last, __len1, __len2, __buf.begin(), _DistanceType(__buf.size()), __comp); } /** * @brief Merges two sorted ranges in place. * @ingroup sorting_algorithms * @param __first An iterator. * @param __middle Another iterator. * @param __last Another iterator. * @return Nothing. * * Merges two sorted and consecutive ranges, [__first,__middle) and * [__middle,__last), and puts the result in [__first,__last). The * output will be sorted. The sort is @e stable, that is, for * equivalent elements in the two ranges, elements from the first * range will always come before elements from the second. * * If enough additional memory is available, this takes (__last-__first)-1 * comparisons. Otherwise an NlogN algorithm is used, where N is * distance(__first,__last). */ template inline void inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_BidirectionalIterator>::value_type>) __glibcxx_requires_sorted(__first, __middle); __glibcxx_requires_sorted(__middle, __last); __glibcxx_requires_irreflexive(__first, __last); std::__inplace_merge(__first, __middle, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Merges two sorted ranges in place. * @ingroup sorting_algorithms * @param __first An iterator. * @param __middle Another iterator. * @param __last Another iterator. * @param __comp A functor to use for comparisons. * @return Nothing. * * Merges two sorted and consecutive ranges, [__first,__middle) and * [middle,last), and puts the result in [__first,__last). The output will * be sorted. The sort is @e stable, that is, for equivalent * elements in the two ranges, elements from the first range will always * come before elements from the second. * * If enough additional memory is available, this takes (__last-__first)-1 * comparisons. Otherwise an NlogN algorithm is used, where N is * distance(__first,__last). * * The comparison function should have the same effects on ordering as * the function used for the initial sort. */ template inline void inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_BidirectionalIterator>::value_type, typename iterator_traits<_BidirectionalIterator>::value_type>) __glibcxx_requires_sorted_pred(__first, __middle, __comp); __glibcxx_requires_sorted_pred(__middle, __last, __comp); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); std::__inplace_merge(__first, __middle, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } /// This is a helper function for the __merge_sort_loop routines. template _OutputIterator __move_merge(_InputIterator __first1, _InputIterator __last1, _InputIterator __first2, _InputIterator __last2, _OutputIterator __result, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) { if (__comp(__first2, __first1)) { *__result = _GLIBCXX_MOVE(*__first2); ++__first2; } else { *__result = _GLIBCXX_MOVE(*__first1); ++__first1; } ++__result; } return _GLIBCXX_MOVE3(__first2, __last2, _GLIBCXX_MOVE3(__first1, __last1, __result)); } template void __merge_sort_loop(_RandomAccessIterator1 __first, _RandomAccessIterator1 __last, _RandomAccessIterator2 __result, _Distance __step_size, _Compare __comp) { const _Distance __two_step = 2 * __step_size; while (__last - __first >= __two_step) { __result = std::__move_merge(__first, __first + __step_size, __first + __step_size, __first + __two_step, __result, __comp); __first += __two_step; } __step_size = std::min(_Distance(__last - __first), __step_size); std::__move_merge(__first, __first + __step_size, __first + __step_size, __last, __result, __comp); } template _GLIBCXX20_CONSTEXPR void __chunk_insertion_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Distance __chunk_size, _Compare __comp) { while (__last - __first >= __chunk_size) { std::__insertion_sort(__first, __first + __chunk_size, __comp); __first += __chunk_size; } std::__insertion_sort(__first, __last, __comp); } enum { _S_chunk_size = 7 }; template void __merge_sort_with_buffer(_RandomAccessIterator __first, _RandomAccessIterator __last, _Pointer __buffer, _Compare __comp) { typedef typename iterator_traits<_RandomAccessIterator>::difference_type _Distance; const _Distance __len = __last - __first; const _Pointer __buffer_last = __buffer + __len; _Distance __step_size = _S_chunk_size; std::__chunk_insertion_sort(__first, __last, __step_size, __comp); while (__step_size < __len) { std::__merge_sort_loop(__first, __last, __buffer, __step_size, __comp); __step_size *= 2; std::__merge_sort_loop(__buffer, __buffer_last, __first, __step_size, __comp); __step_size *= 2; } } template void __stable_sort_adaptive(_RandomAccessIterator __first, _RandomAccessIterator __last, _Pointer __buffer, _Distance __buffer_size, _Compare __comp) { const _Distance __len = (__last - __first + 1) / 2; const _RandomAccessIterator __middle = __first + __len; if (__len > __buffer_size) { std::__stable_sort_adaptive(__first, __middle, __buffer, __buffer_size, __comp); std::__stable_sort_adaptive(__middle, __last, __buffer, __buffer_size, __comp); } else { std::__merge_sort_with_buffer(__first, __middle, __buffer, __comp); std::__merge_sort_with_buffer(__middle, __last, __buffer, __comp); } std::__merge_adaptive(__first, __middle, __last, _Distance(__middle - __first), _Distance(__last - __middle), __buffer, __buffer_size, __comp); } /// This is a helper function for the stable sorting routines. template void __inplace_stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { if (__last - __first < 15) { std::__insertion_sort(__first, __last, __comp); return; } _RandomAccessIterator __middle = __first + (__last - __first) / 2; std::__inplace_stable_sort(__first, __middle, __comp); std::__inplace_stable_sort(__middle, __last, __comp); std::__merge_without_buffer(__first, __middle, __last, __middle - __first, __last - __middle, __comp); } // stable_sort // Set algorithms: includes, set_union, set_intersection, set_difference, // set_symmetric_difference. All of these algorithms have the precondition // that their input ranges are sorted and the postcondition that their output // ranges are sorted. template _GLIBCXX20_CONSTEXPR bool __includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) { if (__comp(__first2, __first1)) return false; if (!__comp(__first1, __first2)) ++__first2; ++__first1; } return __first2 == __last2; } /** * @brief Determines whether all elements of a sequence exists in a range. * @param __first1 Start of search range. * @param __last1 End of search range. * @param __first2 Start of sequence * @param __last2 End of sequence. * @return True if each element in [__first2,__last2) is contained in order * within [__first1,__last1). False otherwise. * @ingroup set_algorithms * * This operation expects both [__first1,__last1) and * [__first2,__last2) to be sorted. Searches for the presence of * each element in [__first2,__last2) within [__first1,__last1). * The iterators over each range only move forward, so this is a * linear algorithm. If an element in [__first2,__last2) is not * found before the search iterator reaches @p __last2, false is * returned. */ template _GLIBCXX20_CONSTEXPR inline bool includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set(__first1, __last1, __first2); __glibcxx_requires_sorted_set(__first2, __last2, __first1); __glibcxx_requires_irreflexive2(__first1, __last1); __glibcxx_requires_irreflexive2(__first2, __last2); return std::__includes(__first1, __last1, __first2, __last2, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Determines whether all elements of a sequence exists in a range * using comparison. * @ingroup set_algorithms * @param __first1 Start of search range. * @param __last1 End of search range. * @param __first2 Start of sequence * @param __last2 End of sequence. * @param __comp Comparison function to use. * @return True if each element in [__first2,__last2) is contained * in order within [__first1,__last1) according to comp. False * otherwise. @ingroup set_algorithms * * This operation expects both [__first1,__last1) and * [__first2,__last2) to be sorted. Searches for the presence of * each element in [__first2,__last2) within [__first1,__last1), * using comp to decide. The iterators over each range only move * forward, so this is a linear algorithm. If an element in * [__first2,__last2) is not found before the search iterator * reaches @p __last2, false is returned. */ template _GLIBCXX20_CONSTEXPR inline bool includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp); __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp); __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp); __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp); return std::__includes(__first1, __last1, __first2, __last2, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } // nth_element // merge // set_difference // set_intersection // set_union // stable_sort // set_symmetric_difference // min_element // max_element template _GLIBCXX20_CONSTEXPR bool __next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) { if (__first == __last) return false; _BidirectionalIterator __i = __first; ++__i; if (__i == __last) return false; __i = __last; --__i; for(;;) { _BidirectionalIterator __ii = __i; --__i; if (__comp(__i, __ii)) { _BidirectionalIterator __j = __last; while (!__comp(__i, --__j)) {} std::iter_swap(__i, __j); std::__reverse(__ii, __last, std::__iterator_category(__first)); return true; } if (__i == __first) { std::__reverse(__first, __last, std::__iterator_category(__first)); return false; } } } /** * @brief Permute range into the next @e dictionary ordering. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @return False if wrapped to first permutation, true otherwise. * * Treats all permutations of the range as a set of @e dictionary sorted * sequences. Permutes the current sequence into the next one of this set. * Returns true if there are more sequences to generate. If the sequence * is the largest of the set, the smallest is generated and false returned. */ template _GLIBCXX20_CONSTEXPR inline bool next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last) { // concept requirements __glibcxx_function_requires(_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_BidirectionalIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); return std::__next_permutation (__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Permute range into the next @e dictionary ordering using * comparison functor. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @param __comp A comparison functor. * @return False if wrapped to first permutation, true otherwise. * * Treats all permutations of the range [__first,__last) as a set of * @e dictionary sorted sequences ordered by @p __comp. Permutes the current * sequence into the next one of this set. Returns true if there are more * sequences to generate. If the sequence is the largest of the set, the * smallest is generated and false returned. */ template _GLIBCXX20_CONSTEXPR inline bool next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_BidirectionalIterator>::value_type, typename iterator_traits<_BidirectionalIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); return std::__next_permutation (__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX20_CONSTEXPR bool __prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) { if (__first == __last) return false; _BidirectionalIterator __i = __first; ++__i; if (__i == __last) return false; __i = __last; --__i; for(;;) { _BidirectionalIterator __ii = __i; --__i; if (__comp(__ii, __i)) { _BidirectionalIterator __j = __last; while (!__comp(--__j, __i)) {} std::iter_swap(__i, __j); std::__reverse(__ii, __last, std::__iterator_category(__first)); return true; } if (__i == __first) { std::__reverse(__first, __last, std::__iterator_category(__first)); return false; } } } /** * @brief Permute range into the previous @e dictionary ordering. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @return False if wrapped to last permutation, true otherwise. * * Treats all permutations of the range as a set of @e dictionary sorted * sequences. Permutes the current sequence into the previous one of this * set. Returns true if there are more sequences to generate. If the * sequence is the smallest of the set, the largest is generated and false * returned. */ template _GLIBCXX20_CONSTEXPR inline bool prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last) { // concept requirements __glibcxx_function_requires(_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_BidirectionalIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); return std::__prev_permutation(__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Permute range into the previous @e dictionary ordering using * comparison functor. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @param __comp A comparison functor. * @return False if wrapped to last permutation, true otherwise. * * Treats all permutations of the range [__first,__last) as a set of * @e dictionary sorted sequences ordered by @p __comp. Permutes the current * sequence into the previous one of this set. Returns true if there are * more sequences to generate. If the sequence is the smallest of the set, * the largest is generated and false returned. */ template _GLIBCXX20_CONSTEXPR inline bool prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_BidirectionalIteratorConcept< _BidirectionalIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_BidirectionalIterator>::value_type, typename iterator_traits<_BidirectionalIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); return std::__prev_permutation(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } // replace // replace_if template _GLIBCXX20_CONSTEXPR _OutputIterator __replace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred, const _Tp& __new_value) { for (; __first != __last; ++__first, (void)++__result) if (__pred(__first)) *__result = __new_value; else *__result = *__first; return __result; } /** * @brief Copy a sequence, replacing each element of one value with another * value. * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @param __old_value The value to be replaced. * @param __new_value The replacement value. * @return The end of the output sequence, @p result+(last-first). * * Copies each element in the input range @p [__first,__last) to the * output range @p [__result,__result+(__last-__first)) replacing elements * equal to @p __old_value with @p __new_value. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator replace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __old_value, const _Tp& __new_value) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_InputIterator>::value_type, _Tp>) __glibcxx_requires_valid_range(__first, __last); return std::__replace_copy_if(__first, __last, __result, __gnu_cxx::__ops::__iter_equals_val(__old_value), __new_value); } /** * @brief Copy a sequence, replacing each value for which a predicate * returns true with another value. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @param __pred A predicate. * @param __new_value The replacement value. * @return The end of the output sequence, @p __result+(__last-__first). * * Copies each element in the range @p [__first,__last) to the range * @p [__result,__result+(__last-__first)) replacing elements for which * @p __pred returns true with @p __new_value. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator replace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred, const _Tp& __new_value) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__replace_copy_if(__first, __last, __result, __gnu_cxx::__ops::__pred_iter(__pred), __new_value); } #if __cplusplus >= 201103L /** * @brief Determines whether the elements of a sequence are sorted. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @return True if the elements are sorted, false otherwise. */ template _GLIBCXX20_CONSTEXPR inline bool is_sorted(_ForwardIterator __first, _ForwardIterator __last) { return std::is_sorted_until(__first, __last) == __last; } /** * @brief Determines whether the elements of a sequence are sorted * according to a comparison functor. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __comp A comparison functor. * @return True if the elements are sorted, false otherwise. */ template _GLIBCXX20_CONSTEXPR inline bool is_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { return std::is_sorted_until(__first, __last, __comp) == __last; } template _GLIBCXX20_CONSTEXPR _ForwardIterator __is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { if (__first == __last) return __last; _ForwardIterator __next = __first; for (++__next; __next != __last; __first = __next, (void)++__next) if (__comp(__next, __first)) return __next; return __next; } /** * @brief Determines the end of a sorted sequence. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @return An iterator pointing to the last iterator i in [__first, __last) * for which the range [__first, i) is sorted. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator is_sorted_until(_ForwardIterator __first, _ForwardIterator __last) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); return std::__is_sorted_until(__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Determines the end of a sorted sequence using comparison functor. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __comp A comparison functor. * @return An iterator pointing to the last iterator i in [__first, __last) * for which the range [__first, i) is sorted. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); return std::__is_sorted_until(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } /** * @brief Determines min and max at once as an ordered pair. * @ingroup sorting_algorithms * @param __a A thing of arbitrary type. * @param __b Another thing of arbitrary type. * @return A pair(__b, __a) if __b is smaller than __a, pair(__a, * __b) otherwise. */ template _GLIBCXX14_CONSTEXPR inline pair minmax(const _Tp& __a, const _Tp& __b) { // concept requirements __glibcxx_function_requires(_LessThanComparableConcept<_Tp>) return __b < __a ? pair(__b, __a) : pair(__a, __b); } /** * @brief Determines min and max at once as an ordered pair. * @ingroup sorting_algorithms * @param __a A thing of arbitrary type. * @param __b Another thing of arbitrary type. * @param __comp A @link comparison_functors comparison functor @endlink. * @return A pair(__b, __a) if __b is smaller than __a, pair(__a, * __b) otherwise. */ template _GLIBCXX14_CONSTEXPR inline pair minmax(const _Tp& __a, const _Tp& __b, _Compare __comp) { return __comp(__b, __a) ? pair(__b, __a) : pair(__a, __b); } template _GLIBCXX14_CONSTEXPR pair<_ForwardIterator, _ForwardIterator> __minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { _ForwardIterator __next = __first; if (__first == __last || ++__next == __last) return std::make_pair(__first, __first); _ForwardIterator __min{}, __max{}; if (__comp(__next, __first)) { __min = __next; __max = __first; } else { __min = __first; __max = __next; } __first = __next; ++__first; while (__first != __last) { __next = __first; if (++__next == __last) { if (__comp(__first, __min)) __min = __first; else if (!__comp(__first, __max)) __max = __first; break; } if (__comp(__next, __first)) { if (__comp(__next, __min)) __min = __next; if (!__comp(__first, __max)) __max = __first; } else { if (__comp(__first, __min)) __min = __first; if (!__comp(__next, __max)) __max = __next; } __first = __next; ++__first; } return std::make_pair(__min, __max); } /** * @brief Return a pair of iterators pointing to the minimum and maximum * elements in a range. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @return make_pair(m, M), where m is the first iterator i in * [__first, __last) such that no other element in the range is * smaller, and where M is the last iterator i in [__first, __last) * such that no other element in the range is larger. */ template _GLIBCXX14_CONSTEXPR inline pair<_ForwardIterator, _ForwardIterator> minmax_element(_ForwardIterator __first, _ForwardIterator __last) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); return std::__minmax_element(__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Return a pair of iterators pointing to the minimum and maximum * elements in a range. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @param __comp Comparison functor. * @return make_pair(m, M), where m is the first iterator i in * [__first, __last) such that no other element in the range is * smaller, and where M is the last iterator i in [__first, __last) * such that no other element in the range is larger. */ template _GLIBCXX14_CONSTEXPR inline pair<_ForwardIterator, _ForwardIterator> minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); return std::__minmax_element(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } // N2722 + DR 915. template _GLIBCXX14_CONSTEXPR inline _Tp min(initializer_list<_Tp> __l) { return *std::min_element(__l.begin(), __l.end()); } template _GLIBCXX14_CONSTEXPR inline _Tp min(initializer_list<_Tp> __l, _Compare __comp) { return *std::min_element(__l.begin(), __l.end(), __comp); } template _GLIBCXX14_CONSTEXPR inline _Tp max(initializer_list<_Tp> __l) { return *std::max_element(__l.begin(), __l.end()); } template _GLIBCXX14_CONSTEXPR inline _Tp max(initializer_list<_Tp> __l, _Compare __comp) { return *std::max_element(__l.begin(), __l.end(), __comp); } template _GLIBCXX14_CONSTEXPR inline pair<_Tp, _Tp> minmax(initializer_list<_Tp> __l) { pair __p = std::minmax_element(__l.begin(), __l.end()); return std::make_pair(*__p.first, *__p.second); } template _GLIBCXX14_CONSTEXPR inline pair<_Tp, _Tp> minmax(initializer_list<_Tp> __l, _Compare __comp) { pair __p = std::minmax_element(__l.begin(), __l.end(), __comp); return std::make_pair(*__p.first, *__p.second); } /** * @brief Checks whether a permutation of the second sequence is equal * to the first sequence. * @ingroup non_mutating_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __pred A binary predicate. * @return true if there exists a permutation of the elements in * the range [__first2, __first2 + (__last1 - __first1)), * beginning with ForwardIterator2 begin, such that * equal(__first1, __last1, __begin, __pred) returns true; * otherwise, returns false. */ template _GLIBCXX20_CONSTEXPR inline bool is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _BinaryPredicate __pred) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>) __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>) __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator1>::value_type, typename iterator_traits<_ForwardIterator2>::value_type>) __glibcxx_requires_valid_range(__first1, __last1); return std::__is_permutation(__first1, __last1, __first2, __gnu_cxx::__ops::__iter_comp_iter(__pred)); } #if __cplusplus > 201103L template _GLIBCXX20_CONSTEXPR bool __is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred) { using _Cat1 = typename iterator_traits<_ForwardIterator1>::iterator_category; using _Cat2 = typename iterator_traits<_ForwardIterator2>::iterator_category; using _It1_is_RA = is_same<_Cat1, random_access_iterator_tag>; using _It2_is_RA = is_same<_Cat2, random_access_iterator_tag>; constexpr bool __ra_iters = _It1_is_RA() && _It2_is_RA(); if (__ra_iters) { auto __d1 = std::distance(__first1, __last1); auto __d2 = std::distance(__first2, __last2); if (__d1 != __d2) return false; } // Efficiently compare identical prefixes: O(N) if sequences // have the same elements in the same order. for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2) if (!__pred(__first1, __first2)) break; if (__ra_iters) { if (__first1 == __last1) return true; } else { auto __d1 = std::distance(__first1, __last1); auto __d2 = std::distance(__first2, __last2); if (__d1 == 0 && __d2 == 0) return true; if (__d1 != __d2) return false; } for (_ForwardIterator1 __scan = __first1; __scan != __last1; ++__scan) { if (__scan != std::__find_if(__first1, __scan, __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan))) continue; // We've seen this one before. auto __matches = std::__count_if(__first2, __last2, __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan)); if (0 == __matches || std::__count_if(__scan, __last1, __gnu_cxx::__ops::__iter_comp_iter(__pred, __scan)) != __matches) return false; } return true; } /** * @brief Checks whether a permutaion of the second sequence is equal * to the first sequence. * @ingroup non_mutating_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of first range. * @return true if there exists a permutation of the elements in the range * [__first2, __last2), beginning with ForwardIterator2 begin, * such that equal(__first1, __last1, begin) returns true; * otherwise, returns false. */ template _GLIBCXX20_CONSTEXPR inline bool is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) { __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); return std::__is_permutation(__first1, __last1, __first2, __last2, __gnu_cxx::__ops::__iter_equal_to_iter()); } /** * @brief Checks whether a permutation of the second sequence is equal * to the first sequence. * @ingroup non_mutating_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of first range. * @param __pred A binary predicate. * @return true if there exists a permutation of the elements in the range * [__first2, __last2), beginning with ForwardIterator2 begin, * such that equal(__first1, __last1, __begin, __pred) returns true; * otherwise, returns false. */ template _GLIBCXX20_CONSTEXPR inline bool is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred) { __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); return std::__is_permutation(__first1, __last1, __first2, __last2, __gnu_cxx::__ops::__iter_comp_iter(__pred)); } #if __cplusplus > 201402L #define __cpp_lib_clamp 201603 /** * @brief Returns the value clamped between lo and hi. * @ingroup sorting_algorithms * @param __val A value of arbitrary type. * @param __lo A lower limit of arbitrary type. * @param __hi An upper limit of arbitrary type. * @return max(__val, __lo) if __val < __hi or min(__val, __hi) otherwise. */ template constexpr const _Tp& clamp(const _Tp& __val, const _Tp& __lo, const _Tp& __hi) { __glibcxx_assert(!(__hi < __lo)); return (__val < __lo) ? __lo : (__hi < __val) ? __hi : __val; } /** * @brief Returns the value clamped between lo and hi. * @ingroup sorting_algorithms * @param __val A value of arbitrary type. * @param __lo A lower limit of arbitrary type. * @param __hi An upper limit of arbitrary type. * @param __comp A comparison functor. * @return max(__val, __lo, __comp) if __comp(__val, __hi) * or min(__val, __hi, __comp) otherwise. */ template constexpr const _Tp& clamp(const _Tp& __val, const _Tp& __lo, const _Tp& __hi, _Compare __comp) { __glibcxx_assert(!__comp(__hi, __lo)); return __comp(__val, __lo) ? __lo : __comp(__hi, __val) ? __hi : __val; } #endif // C++17 #endif // C++14 #ifdef _GLIBCXX_USE_C99_STDINT_TR1 /** * @brief Generate two uniformly distributed integers using a * single distribution invocation. * @param __b0 The upper bound for the first integer. * @param __b1 The upper bound for the second integer. * @param __g A UniformRandomBitGenerator. * @return A pair (i, j) with i and j uniformly distributed * over [0, __b0) and [0, __b1), respectively. * * Requires: __b0 * __b1 <= __g.max() - __g.min(). * * Using uniform_int_distribution with a range that is very * small relative to the range of the generator ends up wasting * potentially expensively generated randomness, since * uniform_int_distribution does not store leftover randomness * between invocations. * * If we know we want two integers in ranges that are sufficiently * small, we can compose the ranges, use a single distribution * invocation, and significantly reduce the waste. */ template pair<_IntType, _IntType> __gen_two_uniform_ints(_IntType __b0, _IntType __b1, _UniformRandomBitGenerator&& __g) { _IntType __x = uniform_int_distribution<_IntType>{0, (__b0 * __b1) - 1}(__g); return std::make_pair(__x / __b1, __x % __b1); } /** * @brief Shuffle the elements of a sequence using a uniform random * number generator. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __g A UniformRandomNumberGenerator (26.5.1.3). * @return Nothing. * * Reorders the elements in the range @p [__first,__last) using @p __g to * provide random numbers. */ template void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last, _UniformRandomNumberGenerator&& __g) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_requires_valid_range(__first, __last); if (__first == __last) return; typedef typename iterator_traits<_RandomAccessIterator>::difference_type _DistanceType; typedef typename std::make_unsigned<_DistanceType>::type __ud_type; typedef typename std::uniform_int_distribution<__ud_type> __distr_type; typedef typename __distr_type::param_type __p_type; typedef typename remove_reference<_UniformRandomNumberGenerator>::type _Gen; typedef typename common_type::type __uc_type; const __uc_type __urngrange = __g.max() - __g.min(); const __uc_type __urange = __uc_type(__last - __first); if (__urngrange / __urange >= __urange) // I.e. (__urngrange >= __urange * __urange) but without wrap issues. { _RandomAccessIterator __i = __first + 1; // Since we know the range isn't empty, an even number of elements // means an uneven number of elements /to swap/, in which case we // do the first one up front: if ((__urange % 2) == 0) { __distr_type __d{0, 1}; std::iter_swap(__i++, __first + __d(__g)); } // Now we know that __last - __i is even, so we do the rest in pairs, // using a single distribution invocation to produce swap positions // for two successive elements at a time: while (__i != __last) { const __uc_type __swap_range = __uc_type(__i - __first) + 1; const pair<__uc_type, __uc_type> __pospos = __gen_two_uniform_ints(__swap_range, __swap_range + 1, __g); std::iter_swap(__i++, __first + __pospos.first); std::iter_swap(__i++, __first + __pospos.second); } return; } __distr_type __d; for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i) std::iter_swap(__i, __first + __d(__g, __p_type(0, __i - __first))); } #endif #endif // C++11 _GLIBCXX_BEGIN_NAMESPACE_ALGO /** * @brief Apply a function to every element of a sequence. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __f A unary function object. * @return @p __f * * Applies the function object @p __f to each element in the range * @p [first,last). @p __f must not modify the order of the sequence. * If @p __f has a return value it is ignored. */ template _GLIBCXX20_CONSTEXPR _Function for_each(_InputIterator __first, _InputIterator __last, _Function __f) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_requires_valid_range(__first, __last); for (; __first != __last; ++__first) __f(*__first); return __f; // N.B. [alg.foreach] says std::move(f) but it's redundant. } #if __cplusplus >= 201703L /** * @brief Apply a function to every element of a sequence. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __n A value convertible to an integer. * @param __f A unary function object. * @return `__first+__n` * * Applies the function object `__f` to each element in the range * `[first, first+n)`. `__f` must not modify the order of the sequence. * If `__f` has a return value it is ignored. */ template _GLIBCXX20_CONSTEXPR _InputIterator for_each_n(_InputIterator __first, _Size __n, _Function __f) { auto __n2 = std::__size_to_integer(__n); using _Cat = typename iterator_traits<_InputIterator>::iterator_category; if constexpr (is_base_of_v) { if (__n2 <= 0) return __first; auto __last = __first + __n2; std::for_each(__first, __last, std::move(__f)); return __last; } else { while (__n2-->0) { __f(*__first); ++__first; } return __first; } } #endif // C++17 /** * @brief Find the first occurrence of a value in a sequence. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __val The value to find. * @return The first iterator @c i in the range @p [__first,__last) * such that @c *i == @p __val, or @p __last if no such iterator exists. */ template _GLIBCXX20_CONSTEXPR inline _InputIterator find(_InputIterator __first, _InputIterator __last, const _Tp& __val) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_InputIterator>::value_type, _Tp>) __glibcxx_requires_valid_range(__first, __last); return std::__find_if(__first, __last, __gnu_cxx::__ops::__iter_equals_val(__val)); } /** * @brief Find the first element in a sequence for which a * predicate is true. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __pred A predicate. * @return The first iterator @c i in the range @p [__first,__last) * such that @p __pred(*i) is true, or @p __last if no such iterator exists. */ template _GLIBCXX20_CONSTEXPR inline _InputIterator find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__find_if(__first, __last, __gnu_cxx::__ops::__pred_iter(__pred)); } /** * @brief Find element from a set in a sequence. * @ingroup non_mutating_algorithms * @param __first1 Start of range to search. * @param __last1 End of range to search. * @param __first2 Start of match candidates. * @param __last2 End of match candidates. * @return The first iterator @c i in the range * @p [__first1,__last1) such that @c *i == @p *(i2) such that i2 is an * iterator in [__first2,__last2), or @p __last1 if no such iterator exists. * * Searches the range @p [__first1,__last1) for an element that is * equal to some element in the range [__first2,__last2). If * found, returns an iterator in the range [__first1,__last1), * otherwise returns @p __last1. */ template _GLIBCXX20_CONSTEXPR _InputIterator find_first_of(_InputIterator __first1, _InputIterator __last1, _ForwardIterator __first2, _ForwardIterator __last2) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_InputIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); for (; __first1 != __last1; ++__first1) for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter) if (*__first1 == *__iter) return __first1; return __last1; } /** * @brief Find element from a set in a sequence using a predicate. * @ingroup non_mutating_algorithms * @param __first1 Start of range to search. * @param __last1 End of range to search. * @param __first2 Start of match candidates. * @param __last2 End of match candidates. * @param __comp Predicate to use. * @return The first iterator @c i in the range * @p [__first1,__last1) such that @c comp(*i, @p *(i2)) is true * and i2 is an iterator in [__first2,__last2), or @p __last1 if no * such iterator exists. * * Searches the range @p [__first1,__last1) for an element that is * equal to some element in the range [__first2,__last2). If * found, returns an iterator in the range [__first1,__last1), * otherwise returns @p __last1. */ template _GLIBCXX20_CONSTEXPR _InputIterator find_first_of(_InputIterator __first1, _InputIterator __last1, _ForwardIterator __first2, _ForwardIterator __last2, _BinaryPredicate __comp) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_InputIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); for (; __first1 != __last1; ++__first1) for (_ForwardIterator __iter = __first2; __iter != __last2; ++__iter) if (__comp(*__first1, *__iter)) return __first1; return __last1; } /** * @brief Find two adjacent values in a sequence that are equal. * @ingroup non_mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @return The first iterator @c i such that @c i and @c i+1 are both * valid iterators in @p [__first,__last) and such that @c *i == @c *(i+1), * or @p __last if no such iterator exists. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator adjacent_find(_ForwardIterator __first, _ForwardIterator __last) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_EqualityComparableConcept< typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__adjacent_find(__first, __last, __gnu_cxx::__ops::__iter_equal_to_iter()); } /** * @brief Find two adjacent values in a sequence using a predicate. * @ingroup non_mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __binary_pred A binary predicate. * @return The first iterator @c i such that @c i and @c i+1 are both * valid iterators in @p [__first,__last) and such that * @p __binary_pred(*i,*(i+1)) is true, or @p __last if no such iterator * exists. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __binary_pred) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__adjacent_find(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__binary_pred)); } /** * @brief Count the number of copies of a value in a sequence. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __value The value to be counted. * @return The number of iterators @c i in the range @p [__first,__last) * for which @c *i == @p __value */ template _GLIBCXX20_CONSTEXPR inline typename iterator_traits<_InputIterator>::difference_type count(_InputIterator __first, _InputIterator __last, const _Tp& __value) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_InputIterator>::value_type, _Tp>) __glibcxx_requires_valid_range(__first, __last); return std::__count_if(__first, __last, __gnu_cxx::__ops::__iter_equals_val(__value)); } /** * @brief Count the elements of a sequence for which a predicate is true. * @ingroup non_mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __pred A predicate. * @return The number of iterators @c i in the range @p [__first,__last) * for which @p __pred(*i) is true. */ template _GLIBCXX20_CONSTEXPR inline typename iterator_traits<_InputIterator>::difference_type count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__count_if(__first, __last, __gnu_cxx::__ops::__pred_iter(__pred)); } /** * @brief Search a sequence for a matching sub-sequence. * @ingroup non_mutating_algorithms * @param __first1 A forward iterator. * @param __last1 A forward iterator. * @param __first2 A forward iterator. * @param __last2 A forward iterator. * @return The first iterator @c i in the range @p * [__first1,__last1-(__last2-__first2)) such that @c *(i+N) == @p * *(__first2+N) for each @c N in the range @p * [0,__last2-__first2), or @p __last1 if no such iterator exists. * * Searches the range @p [__first1,__last1) for a sub-sequence that * compares equal value-by-value with the sequence given by @p * [__first2,__last2) and returns an iterator to the first element * of the sub-sequence, or @p __last1 if the sub-sequence is not * found. * * Because the sub-sequence must lie completely within the range @p * [__first1,__last1) it must start at a position less than @p * __last1-(__last2-__first2) where @p __last2-__first2 is the * length of the sub-sequence. * * This means that the returned iterator @c i will be in the range * @p [__first1,__last1-(__last2-__first2)) */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator1 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>) __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_ForwardIterator1>::value_type, typename iterator_traits<_ForwardIterator2>::value_type>) __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); return std::__search(__first1, __last1, __first2, __last2, __gnu_cxx::__ops::__iter_equal_to_iter()); } /** * @brief Search a sequence for a matching sub-sequence using a predicate. * @ingroup non_mutating_algorithms * @param __first1 A forward iterator. * @param __last1 A forward iterator. * @param __first2 A forward iterator. * @param __last2 A forward iterator. * @param __predicate A binary predicate. * @return The first iterator @c i in the range * @p [__first1,__last1-(__last2-__first2)) such that * @p __predicate(*(i+N),*(__first2+N)) is true for each @c N in the range * @p [0,__last2-__first2), or @p __last1 if no such iterator exists. * * Searches the range @p [__first1,__last1) for a sub-sequence that * compares equal value-by-value with the sequence given by @p * [__first2,__last2), using @p __predicate to determine equality, * and returns an iterator to the first element of the * sub-sequence, or @p __last1 if no such iterator exists. * * @see search(_ForwardIter1, _ForwardIter1, _ForwardIter2, _ForwardIter2) */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator1 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __predicate) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator1>) __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator2>) __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator1>::value_type, typename iterator_traits<_ForwardIterator2>::value_type>) __glibcxx_requires_valid_range(__first1, __last1); __glibcxx_requires_valid_range(__first2, __last2); return std::__search(__first1, __last1, __first2, __last2, __gnu_cxx::__ops::__iter_comp_iter(__predicate)); } /** * @brief Search a sequence for a number of consecutive values. * @ingroup non_mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __count The number of consecutive values. * @param __val The value to find. * @return The first iterator @c i in the range @p * [__first,__last-__count) such that @c *(i+N) == @p __val for * each @c N in the range @p [0,__count), or @p __last if no such * iterator exists. * * Searches the range @p [__first,__last) for @p count consecutive elements * equal to @p __val. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator search_n(_ForwardIterator __first, _ForwardIterator __last, _Integer __count, const _Tp& __val) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_ForwardIterator>::value_type, _Tp>) __glibcxx_requires_valid_range(__first, __last); return std::__search_n(__first, __last, __count, __gnu_cxx::__ops::__iter_equals_val(__val)); } /** * @brief Search a sequence for a number of consecutive values using a * predicate. * @ingroup non_mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __count The number of consecutive values. * @param __val The value to find. * @param __binary_pred A binary predicate. * @return The first iterator @c i in the range @p * [__first,__last-__count) such that @p * __binary_pred(*(i+N),__val) is true for each @c N in the range * @p [0,__count), or @p __last if no such iterator exists. * * Searches the range @p [__first,__last) for @p __count * consecutive elements for which the predicate returns true. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator search_n(_ForwardIterator __first, _ForwardIterator __last, _Integer __count, const _Tp& __val, _BinaryPredicate __binary_pred) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_BinaryPredicate, typename iterator_traits<_ForwardIterator>::value_type, _Tp>) __glibcxx_requires_valid_range(__first, __last); return std::__search_n(__first, __last, __count, __gnu_cxx::__ops::__iter_comp_val(__binary_pred, __val)); } #if __cplusplus >= 201703L /** @brief Search a sequence using a Searcher object. * * @param __first A forward iterator. * @param __last A forward iterator. * @param __searcher A callable object. * @return @p __searcher(__first,__last).first */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator search(_ForwardIterator __first, _ForwardIterator __last, const _Searcher& __searcher) { return __searcher(__first, __last).first; } #endif /** * @brief Perform an operation on a sequence. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @param __unary_op A unary operator. * @return An output iterator equal to @p __result+(__last-__first). * * Applies the operator to each element in the input range and assigns * the results to successive elements of the output sequence. * Evaluates @p *(__result+N)=unary_op(*(__first+N)) for each @c N in the * range @p [0,__last-__first). * * @p unary_op must not alter its argument. */ template _GLIBCXX20_CONSTEXPR _OutputIterator transform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __unary_op) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, // "the type returned by a _UnaryOperation" __typeof__(__unary_op(*__first))>) __glibcxx_requires_valid_range(__first, __last); for (; __first != __last; ++__first, (void)++__result) *__result = __unary_op(*__first); return __result; } /** * @brief Perform an operation on corresponding elements of two sequences. * @ingroup mutating_algorithms * @param __first1 An input iterator. * @param __last1 An input iterator. * @param __first2 An input iterator. * @param __result An output iterator. * @param __binary_op A binary operator. * @return An output iterator equal to @p result+(last-first). * * Applies the operator to the corresponding elements in the two * input ranges and assigns the results to successive elements of the * output sequence. * Evaluates @p * *(__result+N)=__binary_op(*(__first1+N),*(__first2+N)) for each * @c N in the range @p [0,__last1-__first1). * * @p binary_op must not alter either of its arguments. */ template _GLIBCXX20_CONSTEXPR _OutputIterator transform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _OutputIterator __result, _BinaryOperation __binary_op) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, // "the type returned by a _BinaryOperation" __typeof__(__binary_op(*__first1,*__first2))>) __glibcxx_requires_valid_range(__first1, __last1); for (; __first1 != __last1; ++__first1, (void)++__first2, ++__result) *__result = __binary_op(*__first1, *__first2); return __result; } /** * @brief Replace each occurrence of one value in a sequence with another * value. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __old_value The value to be replaced. * @param __new_value The replacement value. * @return replace() returns no value. * * For each iterator @c i in the range @p [__first,__last) if @c *i == * @p __old_value then the assignment @c *i = @p __new_value is performed. */ template _GLIBCXX20_CONSTEXPR void replace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_EqualOpConcept< typename iterator_traits<_ForwardIterator>::value_type, _Tp>) __glibcxx_function_requires(_ConvertibleConcept<_Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); for (; __first != __last; ++__first) if (*__first == __old_value) *__first = __new_value; } /** * @brief Replace each value in a sequence for which a predicate returns * true with another value. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __pred A predicate. * @param __new_value The replacement value. * @return replace_if() returns no value. * * For each iterator @c i in the range @p [__first,__last) if @p __pred(*i) * is true then the assignment @c *i = @p __new_value is performed. */ template _GLIBCXX20_CONSTEXPR void replace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_ConvertibleConcept<_Tp, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); for (; __first != __last; ++__first) if (__pred(*__first)) *__first = __new_value; } /** * @brief Assign the result of a function object to each value in a * sequence. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __gen A function object taking no arguments and returning * std::iterator_traits<_ForwardIterator>::value_type * @return generate() returns no value. * * Performs the assignment @c *i = @p __gen() for each @c i in the range * @p [__first,__last). */ template _GLIBCXX20_CONSTEXPR void generate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_GeneratorConcept<_Generator, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); for (; __first != __last; ++__first) *__first = __gen(); } /** * @brief Assign the result of a function object to each value in a * sequence. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __n The length of the sequence. * @param __gen A function object taking no arguments and returning * std::iterator_traits<_ForwardIterator>::value_type * @return The end of the sequence, @p __first+__n * * Performs the assignment @c *i = @p __gen() for each @c i in the range * @p [__first,__first+__n). * * If @p __n is negative, the function does nothing and returns @p __first. */ // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 865. More algorithms that throw away information // DR 426. search_n(), fill_n(), and generate_n() with negative n template _GLIBCXX20_CONSTEXPR _OutputIterator generate_n(_OutputIterator __first, _Size __n, _Generator __gen) { // concept requirements __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, // "the type returned by a _Generator" __typeof__(__gen())>) typedef __decltype(std::__size_to_integer(__n)) _IntSize; for (_IntSize __niter = std::__size_to_integer(__n); __niter > 0; --__niter, (void) ++__first) *__first = __gen(); return __first; } /** * @brief Copy a sequence, removing consecutive duplicate values. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @return An iterator designating the end of the resulting sequence. * * Copies each element in the range @p [__first,__last) to the range * beginning at @p __result, except that only the first element is copied * from groups of consecutive elements that compare equal. * unique_copy() is stable, so the relative order of elements that are * copied is unchanged. * * _GLIBCXX_RESOLVE_LIB_DEFECTS * DR 241. Does unique_copy() require CopyConstructible and Assignable? * * _GLIBCXX_RESOLVE_LIB_DEFECTS * DR 538. 241 again: Does unique_copy() require CopyConstructible and * Assignable? */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_function_requires(_EqualityComparableConcept< typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); if (__first == __last) return __result; return std::__unique_copy(__first, __last, __result, __gnu_cxx::__ops::__iter_equal_to_iter(), std::__iterator_category(__first), std::__iterator_category(__result)); } /** * @brief Copy a sequence, removing consecutive values using a predicate. * @ingroup mutating_algorithms * @param __first An input iterator. * @param __last An input iterator. * @param __result An output iterator. * @param __binary_pred A binary predicate. * @return An iterator designating the end of the resulting sequence. * * Copies each element in the range @p [__first,__last) to the range * beginning at @p __result, except that only the first element is copied * from groups of consecutive elements for which @p __binary_pred returns * true. * unique_copy() is stable, so the relative order of elements that are * copied is unchanged. * * _GLIBCXX_RESOLVE_LIB_DEFECTS * DR 241. Does unique_copy() require CopyConstructible and Assignable? */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __binary_pred) { // concept requirements -- predicates checked later __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); if (__first == __last) return __result; return std::__unique_copy(__first, __last, __result, __gnu_cxx::__ops::__iter_comp_iter(__binary_pred), std::__iterator_category(__first), std::__iterator_category(__result)); } #if _GLIBCXX_HOSTED /** * @brief Randomly shuffle the elements of a sequence. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @return Nothing. * * Reorder the elements in the range @p [__first,__last) using a random * distribution, so that every possible ordering of the sequence is * equally likely. */ template inline void random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_requires_valid_range(__first, __last); if (__first != __last) for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i) { // XXX rand() % N is not uniformly distributed _RandomAccessIterator __j = __first + std::rand() % ((__i - __first) + 1); if (__i != __j) std::iter_swap(__i, __j); } } #endif /** * @brief Shuffle the elements of a sequence using a random number * generator. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __rand The RNG functor or function. * @return Nothing. * * Reorders the elements in the range @p [__first,__last) using @p __rand to * provide a random distribution. Calling @p __rand(N) for a positive * integer @p N should return a randomly chosen integer from the * range [0,N). */ template void random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last, #if __cplusplus >= 201103L _RandomNumberGenerator&& __rand) #else _RandomNumberGenerator& __rand) #endif { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_requires_valid_range(__first, __last); if (__first == __last) return; for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i) { _RandomAccessIterator __j = __first + __rand((__i - __first) + 1); if (__i != __j) std::iter_swap(__i, __j); } } /** * @brief Move elements for which a predicate is true to the beginning * of a sequence. * @ingroup mutating_algorithms * @param __first A forward iterator. * @param __last A forward iterator. * @param __pred A predicate functor. * @return An iterator @p middle such that @p __pred(i) is true for each * iterator @p i in the range @p [__first,middle) and false for each @p i * in the range @p [middle,__last). * * @p __pred must not modify its operand. @p partition() does not preserve * the relative ordering of elements in each group, use * @p stable_partition() if this is needed. */ template _GLIBCXX20_CONSTEXPR inline _ForwardIterator partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) { // concept requirements __glibcxx_function_requires(_Mutable_ForwardIteratorConcept< _ForwardIterator>) __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); return std::__partition(__first, __last, __pred, std::__iterator_category(__first)); } /** * @brief Sort the smallest elements of a sequence. * @ingroup sorting_algorithms * @param __first An iterator. * @param __middle Another iterator. * @param __last Another iterator. * @return Nothing. * * Sorts the smallest @p (__middle-__first) elements in the range * @p [first,last) and moves them to the range @p [__first,__middle). The * order of the remaining elements in the range @p [__middle,__last) is * undefined. * After the sort if @e i and @e j are iterators in the range * @p [__first,__middle) such that i precedes j and @e k is an iterator in * the range @p [__middle,__last) then *j<*i and *k<*i are both false. */ template _GLIBCXX20_CONSTEXPR inline void partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __middle); __glibcxx_requires_valid_range(__middle, __last); __glibcxx_requires_irreflexive(__first, __last); std::__partial_sort(__first, __middle, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Sort the smallest elements of a sequence using a predicate * for comparison. * @ingroup sorting_algorithms * @param __first An iterator. * @param __middle Another iterator. * @param __last Another iterator. * @param __comp A comparison functor. * @return Nothing. * * Sorts the smallest @p (__middle-__first) elements in the range * @p [__first,__last) and moves them to the range @p [__first,__middle). The * order of the remaining elements in the range @p [__middle,__last) is * undefined. * After the sort if @e i and @e j are iterators in the range * @p [__first,__middle) such that i precedes j and @e k is an iterator in * the range @p [__middle,__last) then @p *__comp(j,*i) and @p __comp(*k,*i) * are both false. */ template _GLIBCXX20_CONSTEXPR inline void partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_RandomAccessIterator>::value_type, typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __middle); __glibcxx_requires_valid_range(__middle, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); std::__partial_sort(__first, __middle, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } /** * @brief Sort a sequence just enough to find a particular position. * @ingroup sorting_algorithms * @param __first An iterator. * @param __nth Another iterator. * @param __last Another iterator. * @return Nothing. * * Rearranges the elements in the range @p [__first,__last) so that @p *__nth * is the same element that would have been in that position had the * whole sequence been sorted. The elements either side of @p *__nth are * not completely sorted, but for any iterator @e i in the range * @p [__first,__nth) and any iterator @e j in the range @p [__nth,__last) it * holds that *j < *i is false. */ template _GLIBCXX20_CONSTEXPR inline void nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __nth); __glibcxx_requires_valid_range(__nth, __last); __glibcxx_requires_irreflexive(__first, __last); if (__first == __last || __nth == __last) return; std::__introselect(__first, __nth, __last, std::__lg(__last - __first) * 2, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Sort a sequence just enough to find a particular position * using a predicate for comparison. * @ingroup sorting_algorithms * @param __first An iterator. * @param __nth Another iterator. * @param __last Another iterator. * @param __comp A comparison functor. * @return Nothing. * * Rearranges the elements in the range @p [__first,__last) so that @p *__nth * is the same element that would have been in that position had the * whole sequence been sorted. The elements either side of @p *__nth are * not completely sorted, but for any iterator @e i in the range * @p [__first,__nth) and any iterator @e j in the range @p [__nth,__last) it * holds that @p __comp(*j,*i) is false. */ template _GLIBCXX20_CONSTEXPR inline void nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_RandomAccessIterator>::value_type, typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __nth); __glibcxx_requires_valid_range(__nth, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); if (__first == __last || __nth == __last) return; std::__introselect(__first, __nth, __last, std::__lg(__last - __first) * 2, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } /** * @brief Sort the elements of a sequence. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @return Nothing. * * Sorts the elements in the range @p [__first,__last) in ascending order, * such that for each iterator @e i in the range @p [__first,__last-1), * *(i+1)<*i is false. * * The relative ordering of equivalent elements is not preserved, use * @p stable_sort() if this is needed. */ template _GLIBCXX20_CONSTEXPR inline void sort(_RandomAccessIterator __first, _RandomAccessIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); std::__sort(__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Sort the elements of a sequence using a predicate for comparison. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __comp A comparison functor. * @return Nothing. * * Sorts the elements in the range @p [__first,__last) in ascending order, * such that @p __comp(*(i+1),*i) is false for every iterator @e i in the * range @p [__first,__last-1). * * The relative ordering of equivalent elements is not preserved, use * @p stable_sort() if this is needed. */ template _GLIBCXX20_CONSTEXPR inline void sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_RandomAccessIterator>::value_type, typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX20_CONSTEXPR _OutputIterator __merge(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) { if (__comp(__first2, __first1)) { *__result = *__first2; ++__first2; } else { *__result = *__first1; ++__first1; } ++__result; } return std::copy(__first2, __last2, std::copy(__first1, __last1, __result)); } /** * @brief Merges two sorted ranges. * @ingroup sorting_algorithms * @param __first1 An iterator. * @param __first2 Another iterator. * @param __last1 Another iterator. * @param __last2 Another iterator. * @param __result An iterator pointing to the end of the merged range. * @return An output iterator equal to @p __result + (__last1 - __first1) * + (__last2 - __first2). * * Merges the ranges @p [__first1,__last1) and @p [__first2,__last2) into * the sorted range @p [__result, __result + (__last1-__first1) + * (__last2-__first2)). Both input ranges must be sorted, and the * output range must not overlap with either of the input ranges. * The sort is @e stable, that is, for equivalent elements in the * two ranges, elements from the first range will always come * before elements from the second. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator merge(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set(__first1, __last1, __first2); __glibcxx_requires_sorted_set(__first2, __last2, __first1); __glibcxx_requires_irreflexive2(__first1, __last1); __glibcxx_requires_irreflexive2(__first2, __last2); return _GLIBCXX_STD_A::__merge(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Merges two sorted ranges. * @ingroup sorting_algorithms * @param __first1 An iterator. * @param __first2 Another iterator. * @param __last1 Another iterator. * @param __last2 Another iterator. * @param __result An iterator pointing to the end of the merged range. * @param __comp A functor to use for comparisons. * @return An output iterator equal to @p __result + (__last1 - __first1) * + (__last2 - __first2). * * Merges the ranges @p [__first1,__last1) and @p [__first2,__last2) into * the sorted range @p [__result, __result + (__last1-__first1) + * (__last2-__first2)). Both input ranges must be sorted, and the * output range must not overlap with either of the input ranges. * The sort is @e stable, that is, for equivalent elements in the * two ranges, elements from the first range will always come * before elements from the second. * * The comparison function should have the same effects on ordering as * the function used for the initial sort. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator merge(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp); __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp); __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp); __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp); return _GLIBCXX_STD_A::__merge(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template inline void __stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { typedef typename iterator_traits<_RandomAccessIterator>::value_type _ValueType; typedef typename iterator_traits<_RandomAccessIterator>::difference_type _DistanceType; typedef _Temporary_buffer<_RandomAccessIterator, _ValueType> _TmpBuf; if (__first == __last) return; // __stable_sort_adaptive sorts the range in two halves, // so the buffer only needs to fit half the range at once. _TmpBuf __buf(__first, (__last - __first + 1) / 2); if (__buf.begin() == 0) std::__inplace_stable_sort(__first, __last, __comp); else std::__stable_sort_adaptive(__first, __last, __buf.begin(), _DistanceType(__buf.size()), __comp); } /** * @brief Sort the elements of a sequence, preserving the relative order * of equivalent elements. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @return Nothing. * * Sorts the elements in the range @p [__first,__last) in ascending order, * such that for each iterator @p i in the range @p [__first,__last-1), * @p *(i+1)<*i is false. * * The relative ordering of equivalent elements is preserved, so any two * elements @p x and @p y in the range @p [__first,__last) such that * @p x inline void stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); _GLIBCXX_STD_A::__stable_sort(__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Sort the elements of a sequence using a predicate for comparison, * preserving the relative order of equivalent elements. * @ingroup sorting_algorithms * @param __first An iterator. * @param __last Another iterator. * @param __comp A comparison functor. * @return Nothing. * * Sorts the elements in the range @p [__first,__last) in ascending order, * such that for each iterator @p i in the range @p [__first,__last-1), * @p __comp(*(i+1),*i) is false. * * The relative ordering of equivalent elements is preserved, so any two * elements @p x and @p y in the range @p [__first,__last) such that * @p __comp(x,y) is false and @p __comp(y,x) is false will have the same * relative ordering after calling @p stable_sort(). */ template inline void stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< _RandomAccessIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_RandomAccessIterator>::value_type, typename iterator_traits<_RandomAccessIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); _GLIBCXX_STD_A::__stable_sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX20_CONSTEXPR _OutputIterator __set_union(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) { if (__comp(__first1, __first2)) { *__result = *__first1; ++__first1; } else if (__comp(__first2, __first1)) { *__result = *__first2; ++__first2; } else { *__result = *__first1; ++__first1; ++__first2; } ++__result; } return std::copy(__first2, __last2, std::copy(__first1, __last1, __result)); } /** * @brief Return the union of two sorted ranges. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * each range in order to the output range. Iterators increment for each * range. When the current element of one range is less than the other, * that element is copied and the iterator advanced. If an element is * contained in both ranges, the element from the first range is copied and * both ranges advance. The output range may not overlap either input * range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_union(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set(__first1, __last1, __first2); __glibcxx_requires_sorted_set(__first2, __last2, __first1); __glibcxx_requires_irreflexive2(__first1, __last1); __glibcxx_requires_irreflexive2(__first2, __last2); return _GLIBCXX_STD_A::__set_union(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Return the union of two sorted ranges using a comparison functor. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @param __comp The comparison functor. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * each range in order to the output range. Iterators increment for each * range. When the current element of one range is less than the other * according to @p __comp, that element is copied and the iterator advanced. * If an equivalent element according to @p __comp is contained in both * ranges, the element from the first range is copied and both ranges * advance. The output range may not overlap either input range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_union(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp); __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp); __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp); __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp); return _GLIBCXX_STD_A::__set_union(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX20_CONSTEXPR _OutputIterator __set_intersection(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) if (__comp(__first1, __first2)) ++__first1; else if (__comp(__first2, __first1)) ++__first2; else { *__result = *__first1; ++__first1; ++__first2; ++__result; } return __result; } /** * @brief Return the intersection of two sorted ranges. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * both ranges in order to the output range. Iterators increment for each * range. When the current element of one range is less than the other, * that iterator advances. If an element is contained in both ranges, the * element from the first range is copied and both ranges advance. The * output range may not overlap either input range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_intersection(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set(__first1, __last1, __first2); __glibcxx_requires_sorted_set(__first2, __last2, __first1); __glibcxx_requires_irreflexive2(__first1, __last1); __glibcxx_requires_irreflexive2(__first2, __last2); return _GLIBCXX_STD_A::__set_intersection(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Return the intersection of two sorted ranges using comparison * functor. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @param __comp The comparison functor. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * both ranges in order to the output range. Iterators increment for each * range. When the current element of one range is less than the other * according to @p __comp, that iterator advances. If an element is * contained in both ranges according to @p __comp, the element from the * first range is copied and both ranges advance. The output range may not * overlap either input range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_intersection(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp); __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp); __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp); __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp); return _GLIBCXX_STD_A::__set_intersection(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX20_CONSTEXPR _OutputIterator __set_difference(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) if (__comp(__first1, __first2)) { *__result = *__first1; ++__first1; ++__result; } else if (__comp(__first2, __first1)) ++__first2; else { ++__first1; ++__first2; } return std::copy(__first1, __last1, __result); } /** * @brief Return the difference of two sorted ranges. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * the first range but not the second in order to the output range. * Iterators increment for each range. When the current element of the * first range is less than the second, that element is copied and the * iterator advances. If the current element of the second range is less, * the iterator advances, but no element is copied. If an element is * contained in both ranges, no elements are copied and both ranges * advance. The output range may not overlap either input range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_difference(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set(__first1, __last1, __first2); __glibcxx_requires_sorted_set(__first2, __last2, __first1); __glibcxx_requires_irreflexive2(__first1, __last1); __glibcxx_requires_irreflexive2(__first2, __last2); return _GLIBCXX_STD_A::__set_difference(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Return the difference of two sorted ranges using comparison * functor. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @param __comp The comparison functor. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * the first range but not the second in order to the output range. * Iterators increment for each range. When the current element of the * first range is less than the second according to @p __comp, that element * is copied and the iterator advances. If the current element of the * second range is less, no element is copied and the iterator advances. * If an element is contained in both ranges according to @p __comp, no * elements are copied and both ranges advance. The output range may not * overlap either input range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_difference(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp); __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp); __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp); __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp); return _GLIBCXX_STD_A::__set_difference(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX20_CONSTEXPR _OutputIterator __set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { while (__first1 != __last1 && __first2 != __last2) if (__comp(__first1, __first2)) { *__result = *__first1; ++__first1; ++__result; } else if (__comp(__first2, __first1)) { *__result = *__first2; ++__first2; ++__result; } else { ++__first1; ++__first2; } return std::copy(__first2, __last2, std::copy(__first1, __last1, __result)); } /** * @brief Return the symmetric difference of two sorted ranges. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * one range but not the other in order to the output range. Iterators * increment for each range. When the current element of one range is less * than the other, that element is copied and the iterator advances. If an * element is contained in both ranges, no elements are copied and both * ranges advance. The output range may not overlap either input range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_LessThanOpConcept< typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set(__first1, __last1, __first2); __glibcxx_requires_sorted_set(__first2, __last2, __first1); __glibcxx_requires_irreflexive2(__first1, __last1); __glibcxx_requires_irreflexive2(__first2, __last2); return _GLIBCXX_STD_A::__set_symmetric_difference(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Return the symmetric difference of two sorted ranges using * comparison functor. * @ingroup set_algorithms * @param __first1 Start of first range. * @param __last1 End of first range. * @param __first2 Start of second range. * @param __last2 End of second range. * @param __result Start of output range. * @param __comp The comparison functor. * @return End of the output range. * @ingroup set_algorithms * * This operation iterates over both ranges, copying elements present in * one range but not the other in order to the output range. Iterators * increment for each range. When the current element of one range is less * than the other according to @p comp, that element is copied and the * iterator advances. If an element is contained in both ranges according * to @p __comp, no elements are copied and both ranges advance. The output * range may not overlap either input range. */ template _GLIBCXX20_CONSTEXPR inline _OutputIterator set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp) { // concept requirements __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>) __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator1>::value_type, typename iterator_traits<_InputIterator2>::value_type>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_InputIterator2>::value_type, typename iterator_traits<_InputIterator1>::value_type>) __glibcxx_requires_sorted_set_pred(__first1, __last1, __first2, __comp); __glibcxx_requires_sorted_set_pred(__first2, __last2, __first1, __comp); __glibcxx_requires_irreflexive_pred2(__first1, __last1, __comp); __glibcxx_requires_irreflexive_pred2(__first2, __last2, __comp); return _GLIBCXX_STD_A::__set_symmetric_difference(__first1, __last1, __first2, __last2, __result, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX14_CONSTEXPR _ForwardIterator __min_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { if (__first == __last) return __first; _ForwardIterator __result = __first; while (++__first != __last) if (__comp(__first, __result)) __result = __first; return __result; } /** * @brief Return the minimum element in a range. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @return Iterator referencing the first instance of the smallest value. */ template _GLIBCXX14_CONSTEXPR _ForwardIterator inline min_element(_ForwardIterator __first, _ForwardIterator __last) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); return _GLIBCXX_STD_A::__min_element(__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Return the minimum element in a range using comparison functor. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @param __comp Comparison functor. * @return Iterator referencing the first instance of the smallest value * according to __comp. */ template _GLIBCXX14_CONSTEXPR inline _ForwardIterator min_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); return _GLIBCXX_STD_A::__min_element(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } template _GLIBCXX14_CONSTEXPR _ForwardIterator __max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { if (__first == __last) return __first; _ForwardIterator __result = __first; while (++__first != __last) if (__comp(__result, __first)) __result = __first; return __result; } /** * @brief Return the maximum element in a range. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @return Iterator referencing the first instance of the largest value. */ template _GLIBCXX14_CONSTEXPR inline _ForwardIterator max_element(_ForwardIterator __first, _ForwardIterator __last) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_LessThanComparableConcept< typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive(__first, __last); return _GLIBCXX_STD_A::__max_element(__first, __last, __gnu_cxx::__ops::__iter_less_iter()); } /** * @brief Return the maximum element in a range using comparison functor. * @ingroup sorting_algorithms * @param __first Start of range. * @param __last End of range. * @param __comp Comparison functor. * @return Iterator referencing the first instance of the largest value * according to __comp. */ template _GLIBCXX14_CONSTEXPR inline _ForwardIterator max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { // concept requirements __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>) __glibcxx_function_requires(_BinaryPredicateConcept<_Compare, typename iterator_traits<_ForwardIterator>::value_type, typename iterator_traits<_ForwardIterator>::value_type>) __glibcxx_requires_valid_range(__first, __last); __glibcxx_requires_irreflexive_pred(__first, __last, __comp); return _GLIBCXX_STD_A::__max_element(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp)); } #if __cplusplus >= 201402L /// Reservoir sampling algorithm. template _RandomAccessIterator __sample(_InputIterator __first, _InputIterator __last, input_iterator_tag, _RandomAccessIterator __out, random_access_iterator_tag, _Size __n, _UniformRandomBitGenerator&& __g) { using __distrib_type = uniform_int_distribution<_Size>; using __param_type = typename __distrib_type::param_type; __distrib_type __d{}; _Size __sample_sz = 0; while (__first != __last && __sample_sz != __n) { __out[__sample_sz++] = *__first; ++__first; } for (auto __pop_sz = __sample_sz; __first != __last; ++__first, (void) ++__pop_sz) { const auto __k = __d(__g, __param_type{0, __pop_sz}); if (__k < __n) __out[__k] = *__first; } return __out + __sample_sz; } /// Selection sampling algorithm. template _OutputIterator __sample(_ForwardIterator __first, _ForwardIterator __last, forward_iterator_tag, _OutputIterator __out, _Cat, _Size __n, _UniformRandomBitGenerator&& __g) { using __distrib_type = uniform_int_distribution<_Size>; using __param_type = typename __distrib_type::param_type; using _USize = make_unsigned_t<_Size>; using _Gen = remove_reference_t<_UniformRandomBitGenerator>; using __uc_type = common_type_t; if (__first == __last) return __out; __distrib_type __d{}; _Size __unsampled_sz = std::distance(__first, __last); __n = std::min(__n, __unsampled_sz); // If possible, we use __gen_two_uniform_ints to efficiently produce // two random numbers using a single distribution invocation: const __uc_type __urngrange = __g.max() - __g.min(); if (__urngrange / __uc_type(__unsampled_sz) >= __uc_type(__unsampled_sz)) // I.e. (__urngrange >= __unsampled_sz * __unsampled_sz) but without // wrapping issues. { while (__n != 0 && __unsampled_sz >= 2) { const pair<_Size, _Size> __p = __gen_two_uniform_ints(__unsampled_sz, __unsampled_sz - 1, __g); --__unsampled_sz; if (__p.first < __n) { *__out++ = *__first; --__n; } ++__first; if (__n == 0) break; --__unsampled_sz; if (__p.second < __n) { *__out++ = *__first; --__n; } ++__first; } } // The loop above is otherwise equivalent to this one-at-a-time version: for (; __n != 0; ++__first) if (__d(__g, __param_type{0, --__unsampled_sz}) < __n) { *__out++ = *__first; --__n; } return __out; } #if __cplusplus > 201402L #define __cpp_lib_sample 201603 /// Take a random sample from a population. template _SampleIterator sample(_PopulationIterator __first, _PopulationIterator __last, _SampleIterator __out, _Distance __n, _UniformRandomBitGenerator&& __g) { using __pop_cat = typename std::iterator_traits<_PopulationIterator>::iterator_category; using __samp_cat = typename std::iterator_traits<_SampleIterator>::iterator_category; static_assert( __or_, is_convertible<__samp_cat, random_access_iterator_tag>>::value, "output range must use a RandomAccessIterator when input range" " does not meet the ForwardIterator requirements"); static_assert(is_integral<_Distance>::value, "sample size must be an integer type"); typename iterator_traits<_PopulationIterator>::difference_type __d = __n; return _GLIBCXX_STD_A:: __sample(__first, __last, __pop_cat{}, __out, __samp_cat{}, __d, std::forward<_UniformRandomBitGenerator>(__g)); } #endif // C++17 #endif // C++14 _GLIBCXX_END_NAMESPACE_ALGO _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif /* _STL_ALGO_H */