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
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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_IS_PERMUTATION_H
#define _LIBCPP___ALGORITHM_IS_PERMUTATION_H
#include <__algorithm/comp.h>
#include <__algorithm/iterator_operations.h>
#include <__config>
#include <__functional/identity.h>
#include <__functional/invoke.h>
#include <__iterator/concepts.h>
#include <__iterator/distance.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/next.h>
#include <__utility/move.h>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class = void>
struct _ConstTimeDistance : false_type {};
#if _LIBCPP_STD_VER > 17
template <class _Iter1, class _Sent1, class _Iter2, class _Sent2>
struct _ConstTimeDistance<_Iter1, _Sent1, _Iter2, _Sent2, __enable_if_t<
sized_sentinel_for<_Sent1, _Iter1> &&
sized_sentinel_for<_Sent2, _Iter2>
>> : true_type {};
#else
template <class _Iter1, class _Iter2>
struct _ConstTimeDistance<_Iter1, _Iter1, _Iter2, _Iter2, __enable_if_t<
is_same<typename iterator_traits<_Iter1>::iterator_category, random_access_iterator_tag>::value &&
is_same<typename iterator_traits<_Iter2>::iterator_category, random_access_iterator_tag>::value
> > : true_type {};
#endif // _LIBCPP_STD_VER > 17
// Internal functions
// For each element in [f1, l1) see if there are the same number of equal elements in [f2, l2)
template <class _AlgPolicy,
class _Iter1, class _Sent1, class _Iter2, class _Sent2,
class _Proj1, class _Proj2, class _Pred>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
__is_permutation_impl(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
_Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2) {
using _D1 = __iter_diff_t<_Iter1>;
for (auto __i = __first1; __i != __last1; ++__i) {
// Have we already counted the number of *__i in [f1, l1)?
auto __match = __first1;
for (; __match != __i; ++__match) {
if (std::__invoke(__pred, std::__invoke(__proj1, *__match), std::__invoke(__proj1, *__i)))
break;
}
if (__match == __i) {
// Count number of *__i in [f2, l2)
_D1 __c2 = 0;
for (auto __j = __first2; __j != __last2; ++__j) {
if (std::__invoke(__pred, std::__invoke(__proj1, *__i), std::__invoke(__proj2, *__j)))
++__c2;
}
if (__c2 == 0)
return false;
// Count number of *__i in [__i, l1) (we can start with 1)
_D1 __c1 = 1;
for (auto __j = _IterOps<_AlgPolicy>::next(__i); __j != __last1; ++__j) {
if (std::__invoke(__pred, std::__invoke(__proj1, *__i), std::__invoke(__proj1, *__j)))
++__c1;
}
if (__c1 != __c2)
return false;
}
}
return true;
}
// 2+1 iterators, predicate. Not used by range algorithms.
template <class _AlgPolicy, class _ForwardIterator1, class _Sentinel1, class _ForwardIterator2, class _BinaryPredicate>
_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
__is_permutation(_ForwardIterator1 __first1, _Sentinel1 __last1, _ForwardIterator2 __first2,
_BinaryPredicate&& __pred) {
// Shorten sequences as much as possible by lopping of any equal prefix.
for (; __first1 != __last1; ++__first1, (void)++__first2) {
if (!__pred(*__first1, *__first2))
break;
}
if (__first1 == __last1)
return true;
// __first1 != __last1 && *__first1 != *__first2
using _D1 = __iter_diff_t<_ForwardIterator1>;
_D1 __l1 = _IterOps<_AlgPolicy>::distance(__first1, __last1);
if (__l1 == _D1(1))
return false;
auto __last2 = _IterOps<_AlgPolicy>::next(__first2, __l1);
return std::__is_permutation_impl<_AlgPolicy>(
std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2),
__pred, __identity(), __identity());
}
// 2+2 iterators, predicate, non-constant time `distance`.
template <class _AlgPolicy,
class _Iter1, class _Sent1, class _Iter2, class _Sent2,
class _Proj1, class _Proj2, class _Pred>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
__is_permutation(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
_Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2,
/*_ConstTimeDistance=*/false_type) {
// Shorten sequences as much as possible by lopping of any equal prefix.
while (__first1 != __last1 && __first2 != __last2) {
if (!std::__invoke(__pred, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2)))
break;
++__first1;
++__first2;
}
if (__first1 == __last1)
return __first2 == __last2;
if (__first2 == __last2) // Second range is shorter
return false;
using _D1 = __iter_diff_t<_Iter1>;
_D1 __l1 = _IterOps<_AlgPolicy>::distance(__first1, __last1);
using _D2 = __iter_diff_t<_Iter2>;
_D2 __l2 = _IterOps<_AlgPolicy>::distance(__first2, __last2);
if (__l1 != __l2)
return false;
return std::__is_permutation_impl<_AlgPolicy>(
std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2),
__pred, __proj1, __proj2);
}
// 2+2 iterators, predicate, specialization for constant-time `distance` call.
template <class _AlgPolicy,
class _Iter1, class _Sent1, class _Iter2, class _Sent2,
class _Proj1, class _Proj2, class _Pred>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
__is_permutation(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
_Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2,
/*_ConstTimeDistance=*/true_type) {
if (std::distance(__first1, __last1) != std::distance(__first2, __last2))
return false;
return std::__is_permutation<_AlgPolicy>(
std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2),
__pred, __proj1, __proj2,
/*_ConstTimeDistance=*/false_type());
}
// 2+2 iterators, predicate
template <class _AlgPolicy,
class _Iter1, class _Sent1, class _Iter2, class _Sent2,
class _Proj1, class _Proj2, class _Pred>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
__is_permutation(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
_Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2) {
return std::__is_permutation<_AlgPolicy>(
std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2),
__pred, __proj1, __proj2,
_ConstTimeDistance<_Iter1, _Sent1, _Iter2, _Sent2>());
}
// Public interface
// 2+1 iterators, predicate
template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
_BinaryPredicate __pred) {
static_assert(__is_callable<_BinaryPredicate, decltype(*__first1), decltype(*__first2)>::value,
"The predicate has to be callable");
return std::__is_permutation<_ClassicAlgPolicy>(
std::move(__first1), std::move(__last1), std::move(__first2), __pred);
}
// 2+1 iterators
template <class _ForwardIterator1, class _ForwardIterator2>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2) {
using __v1 = __iter_value_type<_ForwardIterator1>;
using __v2 = __iter_value_type<_ForwardIterator2>;
return std::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
}
#if _LIBCPP_STD_VER > 11
// 2+2 iterators
template <class _ForwardIterator1, class _ForwardIterator2>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
_ForwardIterator2 __last2) {
using __v1 = __iter_value_type<_ForwardIterator1>;
using __v2 = __iter_value_type<_ForwardIterator2>;
return std::__is_permutation<_ClassicAlgPolicy>(
std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2),
__equal_to<__v1, __v2>(), __identity(), __identity());
}
// 2+2 iterators, predicate
template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
_ForwardIterator2 __last2, _BinaryPredicate __pred) {
static_assert(__is_callable<_BinaryPredicate, decltype(*__first1), decltype(*__first2)>::value,
"The predicate has to be callable");
return std::__is_permutation<_ClassicAlgPolicy>(
std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2),
__pred, __identity(), __identity());
}
#endif // _LIBCPP_STD_VER > 11
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ALGORITHM_IS_PERMUTATION_H
|
