604 lines
19 KiB
Plaintext
604 lines
19 KiB
Plaintext
|
// Algorithm extensions -*- C++ -*-
|
||
|
|
|
||
|
|
// Copyright (C) 2001-2019 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
|
||
|
|
// <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
/*
|
||
|
|
*
|
||
|
|
* 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 ext/algorithm
|
||
|
|
* This file is a GNU extension to the Standard C++ Library (possibly
|
||
|
|
* containing extensions from the HP/SGI STL subset).
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef _EXT_ALGORITHM
|
||
|
|
#define _EXT_ALGORITHM 1
|
||
|
|
|
||
|
|
#pragma GCC system_header
|
||
|
|
|
||
|
|
#include <algorithm>
|
||
|
|
|
||
|
|
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
|
||
|
|
{
|
||
|
|
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||
|
|
|
||
|
|
using std::ptrdiff_t;
|
||
|
|
using std::min;
|
||
|
|
using std::pair;
|
||
|
|
using std::input_iterator_tag;
|
||
|
|
using std::random_access_iterator_tag;
|
||
|
|
using std::iterator_traits;
|
||
|
|
|
||
|
|
//--------------------------------------------------
|
||
|
|
// copy_n (not part of the C++ standard)
|
||
|
|
|
||
|
|
template<typename _InputIterator, typename _Size, typename _OutputIterator>
|
||
|
|
pair<_InputIterator, _OutputIterator>
|
||
|
|
__copy_n(_InputIterator __first, _Size __count,
|
||
|
|
_OutputIterator __result,
|
||
|
|
input_iterator_tag)
|
||
|
|
{
|
||
|
|
for ( ; __count > 0; --__count)
|
||
|
|
{
|
||
|
|
*__result = *__first;
|
||
|
|
++__first;
|
||
|
|
++__result;
|
||
|
|
}
|
||
|
|
return pair<_InputIterator, _OutputIterator>(__first, __result);
|
||
|
|
}
|
||
|
|
|
||
|
|
template<typename _RAIterator, typename _Size, typename _OutputIterator>
|
||
|
|
inline pair<_RAIterator, _OutputIterator>
|
||
|
|
__copy_n(_RAIterator __first, _Size __count,
|
||
|
|
_OutputIterator __result,
|
||
|
|
random_access_iterator_tag)
|
||
|
|
{
|
||
|
|
_RAIterator __last = __first + __count;
|
||
|
|
return pair<_RAIterator, _OutputIterator>(__last, std::copy(__first,
|
||
|
|
__last,
|
||
|
|
__result));
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief Copies the range [first,first+count) into [result,result+count).
|
||
|
|
* @param __first An input iterator.
|
||
|
|
* @param __count The number of elements to copy.
|
||
|
|
* @param __result An output iterator.
|
||
|
|
* @return A std::pair composed of first+count and result+count.
|
||
|
|
*
|
||
|
|
* This is an SGI extension.
|
||
|
|
* 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).
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
*/
|
||
|
|
template<typename _InputIterator, typename _Size, typename _OutputIterator>
|
||
|
|
inline pair<_InputIterator, _OutputIterator>
|
||
|
|
copy_n(_InputIterator __first, _Size __count, _OutputIterator __result)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
|
||
|
|
__glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
|
||
|
|
typename iterator_traits<_InputIterator>::value_type>)
|
||
|
|
|
||
|
|
return __gnu_cxx::__copy_n(__first, __count, __result,
|
||
|
|
std::__iterator_category(__first));
|
||
|
|
}
|
||
|
|
|
||
|
|
template<typename _InputIterator1, typename _InputIterator2>
|
||
|
|
int
|
||
|
|
__lexicographical_compare_3way(_InputIterator1 __first1,
|
||
|
|
_InputIterator1 __last1,
|
||
|
|
_InputIterator2 __first2,
|
||
|
|
_InputIterator2 __last2)
|
||
|
|
{
|
||
|
|
while (__first1 != __last1 && __first2 != __last2)
|
||
|
|
{
|
||
|
|
if (*__first1 < *__first2)
|
||
|
|
return -1;
|
||
|
|
if (*__first2 < *__first1)
|
||
|
|
return 1;
|
||
|
|
++__first1;
|
||
|
|
++__first2;
|
||
|
|
}
|
||
|
|
if (__first2 == __last2)
|
||
|
|
return !(__first1 == __last1);
|
||
|
|
else
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline int
|
||
|
|
__lexicographical_compare_3way(const unsigned char* __first1,
|
||
|
|
const unsigned char* __last1,
|
||
|
|
const unsigned char* __first2,
|
||
|
|
const unsigned char* __last2)
|
||
|
|
{
|
||
|
|
const ptrdiff_t __len1 = __last1 - __first1;
|
||
|
|
const ptrdiff_t __len2 = __last2 - __first2;
|
||
|
|
const int __result = __builtin_memcmp(__first1, __first2,
|
||
|
|
min(__len1, __len2));
|
||
|
|
return __result != 0 ? __result
|
||
|
|
: (__len1 == __len2 ? 0 : (__len1 < __len2 ? -1 : 1));
|
||
|
|
}
|
||
|
|
|
||
|
|
inline int
|
||
|
|
__lexicographical_compare_3way(const char* __first1, const char* __last1,
|
||
|
|
const char* __first2, const char* __last2)
|
||
|
|
{
|
||
|
|
#if CHAR_MAX == SCHAR_MAX
|
||
|
|
return __lexicographical_compare_3way((const signed char*) __first1,
|
||
|
|
(const signed char*) __last1,
|
||
|
|
(const signed char*) __first2,
|
||
|
|
(const signed char*) __last2);
|
||
|
|
#else
|
||
|
|
return __lexicographical_compare_3way((const unsigned char*) __first1,
|
||
|
|
(const unsigned char*) __last1,
|
||
|
|
(const unsigned char*) __first2,
|
||
|
|
(const unsigned char*) __last2);
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief @c memcmp on steroids.
|
||
|
|
* @param __first1 An input iterator.
|
||
|
|
* @param __last1 An input iterator.
|
||
|
|
* @param __first2 An input iterator.
|
||
|
|
* @param __last2 An input iterator.
|
||
|
|
* @return An int, as with @c memcmp.
|
||
|
|
*
|
||
|
|
* The return value will be less than zero if the first range is
|
||
|
|
* <em>lexigraphically less than</em> the second, greater than zero
|
||
|
|
* if the second range is <em>lexigraphically less than</em> the
|
||
|
|
* first, and zero otherwise.
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
*/
|
||
|
|
template<typename _InputIterator1, typename _InputIterator2>
|
||
|
|
int
|
||
|
|
lexicographical_compare_3way(_InputIterator1 __first1,
|
||
|
|
_InputIterator1 __last1,
|
||
|
|
_InputIterator2 __first2,
|
||
|
|
_InputIterator2 __last2)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
|
||
|
|
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
|
||
|
|
__glibcxx_function_requires(_LessThanComparableConcept<
|
||
|
|
typename iterator_traits<_InputIterator1>::value_type>)
|
||
|
|
__glibcxx_function_requires(_LessThanComparableConcept<
|
||
|
|
typename iterator_traits<_InputIterator2>::value_type>)
|
||
|
|
__glibcxx_requires_valid_range(__first1, __last1);
|
||
|
|
__glibcxx_requires_valid_range(__first2, __last2);
|
||
|
|
|
||
|
|
return __lexicographical_compare_3way(__first1, __last1, __first2,
|
||
|
|
__last2);
|
||
|
|
}
|
||
|
|
|
||
|
|
// count and count_if: this version, whose return type is void, was present
|
||
|
|
// in the HP STL, and is retained as an extension for backward compatibility.
|
||
|
|
template<typename _InputIterator, typename _Tp, typename _Size>
|
||
|
|
void
|
||
|
|
count(_InputIterator __first, _InputIterator __last,
|
||
|
|
const _Tp& __value,
|
||
|
|
_Size& __n)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
|
||
|
|
__glibcxx_function_requires(_EqualityComparableConcept<
|
||
|
|
typename iterator_traits<_InputIterator>::value_type >)
|
||
|
|
__glibcxx_function_requires(_EqualityComparableConcept<_Tp>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
|
||
|
|
for ( ; __first != __last; ++__first)
|
||
|
|
if (*__first == __value)
|
||
|
|
++__n;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<typename _InputIterator, typename _Predicate, typename _Size>
|
||
|
|
void
|
||
|
|
count_if(_InputIterator __first, _InputIterator __last,
|
||
|
|
_Predicate __pred,
|
||
|
|
_Size& __n)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
|
||
|
|
__glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
|
||
|
|
typename iterator_traits<_InputIterator>::value_type>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
|
||
|
|
for ( ; __first != __last; ++__first)
|
||
|
|
if (__pred(*__first))
|
||
|
|
++__n;
|
||
|
|
}
|
||
|
|
|
||
|
|
// random_sample and random_sample_n (extensions, not part of the standard).
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _ForwardIterator, typename _OutputIterator,
|
||
|
|
typename _Distance>
|
||
|
|
_OutputIterator
|
||
|
|
random_sample_n(_ForwardIterator __first, _ForwardIterator __last,
|
||
|
|
_OutputIterator __out, const _Distance __n)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
|
||
|
|
__glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
|
||
|
|
typename iterator_traits<_ForwardIterator>::value_type>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
|
||
|
|
_Distance __remaining = std::distance(__first, __last);
|
||
|
|
_Distance __m = min(__n, __remaining);
|
||
|
|
|
||
|
|
while (__m > 0)
|
||
|
|
{
|
||
|
|
if ((std::rand() % __remaining) < __m)
|
||
|
|
{
|
||
|
|
*__out = *__first;
|
||
|
|
++__out;
|
||
|
|
--__m;
|
||
|
|
}
|
||
|
|
--__remaining;
|
||
|
|
++__first;
|
||
|
|
}
|
||
|
|
return __out;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _ForwardIterator, typename _OutputIterator,
|
||
|
|
typename _Distance, typename _RandomNumberGenerator>
|
||
|
|
_OutputIterator
|
||
|
|
random_sample_n(_ForwardIterator __first, _ForwardIterator __last,
|
||
|
|
_OutputIterator __out, const _Distance __n,
|
||
|
|
_RandomNumberGenerator& __rand)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
|
||
|
|
__glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
|
||
|
|
typename iterator_traits<_ForwardIterator>::value_type>)
|
||
|
|
__glibcxx_function_requires(_UnaryFunctionConcept<
|
||
|
|
_RandomNumberGenerator, _Distance, _Distance>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
|
||
|
|
_Distance __remaining = std::distance(__first, __last);
|
||
|
|
_Distance __m = min(__n, __remaining);
|
||
|
|
|
||
|
|
while (__m > 0)
|
||
|
|
{
|
||
|
|
if (__rand(__remaining) < __m)
|
||
|
|
{
|
||
|
|
*__out = *__first;
|
||
|
|
++__out;
|
||
|
|
--__m;
|
||
|
|
}
|
||
|
|
--__remaining;
|
||
|
|
++__first;
|
||
|
|
}
|
||
|
|
return __out;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<typename _InputIterator, typename _RandomAccessIterator,
|
||
|
|
typename _Distance>
|
||
|
|
_RandomAccessIterator
|
||
|
|
__random_sample(_InputIterator __first, _InputIterator __last,
|
||
|
|
_RandomAccessIterator __out,
|
||
|
|
const _Distance __n)
|
||
|
|
{
|
||
|
|
_Distance __m = 0;
|
||
|
|
_Distance __t = __n;
|
||
|
|
for ( ; __first != __last && __m < __n; ++__m, ++__first)
|
||
|
|
__out[__m] = *__first;
|
||
|
|
|
||
|
|
while (__first != __last)
|
||
|
|
{
|
||
|
|
++__t;
|
||
|
|
_Distance __M = std::rand() % (__t);
|
||
|
|
if (__M < __n)
|
||
|
|
__out[__M] = *__first;
|
||
|
|
++__first;
|
||
|
|
}
|
||
|
|
return __out + __m;
|
||
|
|
}
|
||
|
|
|
||
|
|
template<typename _InputIterator, typename _RandomAccessIterator,
|
||
|
|
typename _RandomNumberGenerator, typename _Distance>
|
||
|
|
_RandomAccessIterator
|
||
|
|
__random_sample(_InputIterator __first, _InputIterator __last,
|
||
|
|
_RandomAccessIterator __out,
|
||
|
|
_RandomNumberGenerator& __rand,
|
||
|
|
const _Distance __n)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_UnaryFunctionConcept<
|
||
|
|
_RandomNumberGenerator, _Distance, _Distance>)
|
||
|
|
|
||
|
|
_Distance __m = 0;
|
||
|
|
_Distance __t = __n;
|
||
|
|
for ( ; __first != __last && __m < __n; ++__m, ++__first)
|
||
|
|
__out[__m] = *__first;
|
||
|
|
|
||
|
|
while (__first != __last)
|
||
|
|
{
|
||
|
|
++__t;
|
||
|
|
_Distance __M = __rand(__t);
|
||
|
|
if (__M < __n)
|
||
|
|
__out[__M] = *__first;
|
||
|
|
++__first;
|
||
|
|
}
|
||
|
|
return __out + __m;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _InputIterator, typename _RandomAccessIterator>
|
||
|
|
inline _RandomAccessIterator
|
||
|
|
random_sample(_InputIterator __first, _InputIterator __last,
|
||
|
|
_RandomAccessIterator __out_first,
|
||
|
|
_RandomAccessIterator __out_last)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
|
||
|
|
__glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
|
||
|
|
_RandomAccessIterator>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
__glibcxx_requires_valid_range(__out_first, __out_last);
|
||
|
|
|
||
|
|
return __random_sample(__first, __last,
|
||
|
|
__out_first, __out_last - __out_first);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _InputIterator, typename _RandomAccessIterator,
|
||
|
|
typename _RandomNumberGenerator>
|
||
|
|
inline _RandomAccessIterator
|
||
|
|
random_sample(_InputIterator __first, _InputIterator __last,
|
||
|
|
_RandomAccessIterator __out_first,
|
||
|
|
_RandomAccessIterator __out_last,
|
||
|
|
_RandomNumberGenerator& __rand)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
|
||
|
|
__glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
|
||
|
|
_RandomAccessIterator>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
__glibcxx_requires_valid_range(__out_first, __out_last);
|
||
|
|
|
||
|
|
return __random_sample(__first, __last,
|
||
|
|
__out_first, __rand,
|
||
|
|
__out_last - __out_first);
|
||
|
|
}
|
||
|
|
|
||
|
|
#if __cplusplus >= 201103L
|
||
|
|
using std::is_heap;
|
||
|
|
#else
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _RandomAccessIterator>
|
||
|
|
inline bool
|
||
|
|
is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_RandomAccessIteratorConcept<
|
||
|
|
_RandomAccessIterator>)
|
||
|
|
__glibcxx_function_requires(_LessThanComparableConcept<
|
||
|
|
typename iterator_traits<_RandomAccessIterator>::value_type>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
|
||
|
|
return std::__is_heap(__first, __last - __first);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _RandomAccessIterator, typename _StrictWeakOrdering>
|
||
|
|
inline bool
|
||
|
|
is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last,
|
||
|
|
_StrictWeakOrdering __comp)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_RandomAccessIteratorConcept<
|
||
|
|
_RandomAccessIterator>)
|
||
|
|
__glibcxx_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
|
||
|
|
typename iterator_traits<_RandomAccessIterator>::value_type,
|
||
|
|
typename iterator_traits<_RandomAccessIterator>::value_type>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
|
||
|
|
return std::__is_heap(__first, __comp, __last - __first);
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#if __cplusplus >= 201103L
|
||
|
|
using std::is_sorted;
|
||
|
|
#else
|
||
|
|
// is_sorted, a predicated testing whether a range is sorted in
|
||
|
|
// nondescending order. This is an extension, not part of the C++
|
||
|
|
// standard.
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _ForwardIterator>
|
||
|
|
bool
|
||
|
|
is_sorted(_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);
|
||
|
|
|
||
|
|
if (__first == __last)
|
||
|
|
return true;
|
||
|
|
|
||
|
|
_ForwardIterator __next = __first;
|
||
|
|
for (++__next; __next != __last; __first = __next, ++__next)
|
||
|
|
if (*__next < *__first)
|
||
|
|
return false;
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
* @doctodo
|
||
|
|
*/
|
||
|
|
template<typename _ForwardIterator, typename _StrictWeakOrdering>
|
||
|
|
bool
|
||
|
|
is_sorted(_ForwardIterator __first, _ForwardIterator __last,
|
||
|
|
_StrictWeakOrdering __comp)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
|
||
|
|
__glibcxx_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
|
||
|
|
typename iterator_traits<_ForwardIterator>::value_type,
|
||
|
|
typename iterator_traits<_ForwardIterator>::value_type>)
|
||
|
|
__glibcxx_requires_valid_range(__first, __last);
|
||
|
|
|
||
|
|
if (__first == __last)
|
||
|
|
return true;
|
||
|
|
|
||
|
|
_ForwardIterator __next = __first;
|
||
|
|
for (++__next; __next != __last; __first = __next, ++__next)
|
||
|
|
if (__comp(*__next, *__first))
|
||
|
|
return false;
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
#endif // C++11
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief Find the median of three values.
|
||
|
|
* @param __a A value.
|
||
|
|
* @param __b A value.
|
||
|
|
* @param __c A value.
|
||
|
|
* @return One of @p a, @p b or @p c.
|
||
|
|
*
|
||
|
|
* If @c {l,m,n} is some convolution of @p {a,b,c} such that @c l<=m<=n
|
||
|
|
* then the value returned will be @c m.
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
*/
|
||
|
|
template<typename _Tp>
|
||
|
|
const _Tp&
|
||
|
|
__median(const _Tp& __a, const _Tp& __b, const _Tp& __c)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
|
||
|
|
if (__a < __b)
|
||
|
|
if (__b < __c)
|
||
|
|
return __b;
|
||
|
|
else if (__a < __c)
|
||
|
|
return __c;
|
||
|
|
else
|
||
|
|
return __a;
|
||
|
|
else if (__a < __c)
|
||
|
|
return __a;
|
||
|
|
else if (__b < __c)
|
||
|
|
return __c;
|
||
|
|
else
|
||
|
|
return __b;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief Find the median of three values using a predicate for comparison.
|
||
|
|
* @param __a A value.
|
||
|
|
* @param __b A value.
|
||
|
|
* @param __c A value.
|
||
|
|
* @param __comp A binary predicate.
|
||
|
|
* @return One of @p a, @p b or @p c.
|
||
|
|
*
|
||
|
|
* If @c {l,m,n} is some convolution of @p {a,b,c} such that @p comp(l,m)
|
||
|
|
* and @p comp(m,n) are both true then the value returned will be @c m.
|
||
|
|
* This is an SGI extension.
|
||
|
|
* @ingroup SGIextensions
|
||
|
|
*/
|
||
|
|
template<typename _Tp, typename _Compare>
|
||
|
|
const _Tp&
|
||
|
|
__median(const _Tp& __a, const _Tp& __b, const _Tp& __c, _Compare __comp)
|
||
|
|
{
|
||
|
|
// concept requirements
|
||
|
|
__glibcxx_function_requires(_BinaryFunctionConcept<_Compare, bool,
|
||
|
|
_Tp, _Tp>)
|
||
|
|
if (__comp(__a, __b))
|
||
|
|
if (__comp(__b, __c))
|
||
|
|
return __b;
|
||
|
|
else if (__comp(__a, __c))
|
||
|
|
return __c;
|
||
|
|
else
|
||
|
|
return __a;
|
||
|
|
else if (__comp(__a, __c))
|
||
|
|
return __a;
|
||
|
|
else if (__comp(__b, __c))
|
||
|
|
return __c;
|
||
|
|
else
|
||
|
|
return __b;
|
||
|
|
}
|
||
|
|
|
||
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
||
|
|
} // namespace
|
||
|
|
|
||
|
|
#endif /* _EXT_ALGORITHM */
|