1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221
|
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___ALGORITHM_ROTATE_H
#define _LIBCPP___ALGORITHM_ROTATE_H
#include <__algorithm/iterator_operations.h>
#include <__algorithm/move.h>
#include <__algorithm/move_backward.h>
#include <__algorithm/swap_ranges.h>
#include <__config>
#include <__iterator/iterator_traits.h>
#include <__utility/move.h>
#include <__utility/pair.h>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _AlgPolicy, class _ForwardIterator>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
{
typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
using _Ops = _IterOps<_AlgPolicy>;
value_type __tmp = _Ops::__iter_move(__first);
_ForwardIterator __lm1 = std::__move<_AlgPolicy>(
_Ops::next(__first), __last, __first).second;
*__lm1 = _VSTD::move(__tmp);
return __lm1;
}
template <class _AlgPolicy, class _BidirectionalIterator>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
{
typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
using _Ops = _IterOps<_AlgPolicy>;
_BidirectionalIterator __lm1 = _Ops::prev(__last);
value_type __tmp = _Ops::__iter_move(__lm1);
_BidirectionalIterator __fp1 = std::__move_backward<_AlgPolicy>(__first, __lm1, std::move(__last));
*__first = _VSTD::move(__tmp);
return __fp1;
}
template <class _AlgPolicy, class _ForwardIterator>
_LIBCPP_CONSTEXPR_AFTER_CXX14 _ForwardIterator
__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
{
_ForwardIterator __i = __middle;
while (true)
{
_IterOps<_AlgPolicy>::iter_swap(__first, __i);
++__first;
if (++__i == __last)
break;
if (__first == __middle)
__middle = __i;
}
_ForwardIterator __r = __first;
if (__first != __middle)
{
__i = __middle;
while (true)
{
_IterOps<_AlgPolicy>::iter_swap(__first, __i);
++__first;
if (++__i == __last)
{
if (__first == __middle)
break;
__i = __middle;
}
else if (__first == __middle)
__middle = __i;
}
}
return __r;
}
template<typename _Integral>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX14 _Integral
__algo_gcd(_Integral __x, _Integral __y)
{
do
{
_Integral __t = __x % __y;
__x = __y;
__y = __t;
} while (__y);
return __x;
}
template <class _AlgPolicy, typename _RandomAccessIterator>
_LIBCPP_CONSTEXPR_AFTER_CXX14 _RandomAccessIterator
__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
{
typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
using _Ops = _IterOps<_AlgPolicy>;
const difference_type __m1 = __middle - __first;
const difference_type __m2 = _Ops::distance(__middle, __last);
if (__m1 == __m2)
{
std::__swap_ranges<_AlgPolicy>(__first, __middle, __middle, __last);
return __middle;
}
const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
for (_RandomAccessIterator __p = __first + __g; __p != __first;)
{
value_type __t(_Ops::__iter_move(--__p));
_RandomAccessIterator __p1 = __p;
_RandomAccessIterator __p2 = __p1 + __m1;
do
{
*__p1 = _Ops::__iter_move(__p2);
__p1 = __p2;
const difference_type __d = _Ops::distance(__p2, __last);
if (__m1 < __d)
__p2 += __m1;
else
__p2 = __first + (__m1 - __d);
} while (__p2 != __p);
*__p1 = _VSTD::move(__t);
}
return __first + __m2;
}
template <class _AlgPolicy, class _ForwardIterator>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
__rotate_impl(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
_VSTD::forward_iterator_tag)
{
typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
if (is_trivially_move_assignable<value_type>::value)
{
if (_IterOps<_AlgPolicy>::next(__first) == __middle)
return std::__rotate_left<_AlgPolicy>(__first, __last);
}
return std::__rotate_forward<_AlgPolicy>(__first, __middle, __last);
}
template <class _AlgPolicy, class _BidirectionalIterator>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
__rotate_impl(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
bidirectional_iterator_tag)
{
typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
if (is_trivially_move_assignable<value_type>::value)
{
if (_IterOps<_AlgPolicy>::next(__first) == __middle)
return std::__rotate_left<_AlgPolicy>(__first, __last);
if (_IterOps<_AlgPolicy>::next(__middle) == __last)
return std::__rotate_right<_AlgPolicy>(__first, __last);
}
return std::__rotate_forward<_AlgPolicy>(__first, __middle, __last);
}
template <class _AlgPolicy, class _RandomAccessIterator>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator
__rotate_impl(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
random_access_iterator_tag)
{
typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
if (is_trivially_move_assignable<value_type>::value)
{
if (_IterOps<_AlgPolicy>::next(__first) == __middle)
return std::__rotate_left<_AlgPolicy>(__first, __last);
if (_IterOps<_AlgPolicy>::next(__middle) == __last)
return std::__rotate_right<_AlgPolicy>(__first, __last);
return std::__rotate_gcd<_AlgPolicy>(__first, __middle, __last);
}
return std::__rotate_forward<_AlgPolicy>(__first, __middle, __last);
}
template <class _AlgPolicy, class _Iterator, class _Sentinel>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
pair<_Iterator, _Iterator>
__rotate(_Iterator __first, _Iterator __middle, _Sentinel __last) {
using _Ret = pair<_Iterator, _Iterator>;
_Iterator __last_iter = _IterOps<_AlgPolicy>::next(__middle, __last);
if (__first == __middle)
return _Ret(__last_iter, __last_iter);
if (__middle == __last)
return _Ret(std::move(__first), std::move(__last_iter));
using _IterCategory = typename _IterOps<_AlgPolicy>::template __iterator_category<_Iterator>;
auto __result = std::__rotate_impl<_AlgPolicy>(
std::move(__first), std::move(__middle), __last_iter, _IterCategory());
return _Ret(std::move(__result), std::move(__last_iter));
}
template <class _ForwardIterator>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
{
return std::__rotate<_ClassicAlgPolicy>(
std::move(__first), std::move(__middle), std::move(__last)).first;
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ALGORITHM_ROTATE_H
|