0,0 → 1,603 |
// Algorithm extensions -*- C++ -*- |
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// Copyright (C) 2001-2015 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. |
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// 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. |
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// 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. |
*/ |
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/** @file ext/algorithm |
* This file is a GNU extension to the Standard C++ Library (possibly |
* containing extensions from the HP/SGI STL subset). |
*/ |
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#ifndef _EXT_ALGORITHM |
#define _EXT_ALGORITHM 1 |
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#pragma GCC system_header |
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#include <algorithm> |
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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); |
} |
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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 |
} |
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/** |
* @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); |
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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); |
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for ( ; __first != __last; ++__first) |
if (*__first == __value) |
++__n; |
} |
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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); |
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for ( ; __first != __last; ++__first) |
if (__pred(*__first)) |
++__n; |
} |
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// 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); |
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_Distance __remaining = std::distance(__first, __last); |
_Distance __m = min(__n, __remaining); |
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while (__m > 0) |
{ |
if ((std::rand() % __remaining) < __m) |
{ |
*__out = *__first; |
++__out; |
--__m; |
} |
--__remaining; |
++__first; |
} |
return __out; |
} |
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/** |
* 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); |
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_Distance __remaining = std::distance(__first, __last); |
_Distance __m = min(__n, __remaining); |
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while (__m > 0) |
{ |
if (__rand(__remaining) < __m) |
{ |
*__out = *__first; |
++__out; |
--__m; |
} |
--__remaining; |
++__first; |
} |
return __out; |
} |
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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; |
} |
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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; |
} |
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/** |
* 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); |
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return __random_sample(__first, __last, |
__out_first, __out_last - __out_first); |
} |
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/** |
* 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); |
} |
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#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); |
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return std::__is_heap(__first, __last - __first); |
} |
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/** |
* 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); |
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return std::__is_heap(__first, __comp, __last - __first); |
} |
#endif |
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#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); |
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if (__first == __last) |
return true; |
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_ForwardIterator __next = __first; |
for (++__next; __next != __last; __first = __next, ++__next) |
if (*__next < *__first) |
return false; |
return true; |
} |
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/** |
* 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); |
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if (__first == __last) |
return true; |
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_ForwardIterator __next = __first; |
for (++__next; __next != __last; __first = __next, ++__next) |
if (__comp(*__next, *__first)) |
return false; |
return true; |
} |
#endif // C++11 |
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/** |
* @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; |
} |
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/** |
* @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; |
} |
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_GLIBCXX_END_NAMESPACE_VERSION |
} // namespace |
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#endif /* _EXT_ALGORITHM */ |