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
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
|
//===----------------------------------------------------------------------===//
//
// 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___RANDOM_DISCRETE_DISTRIBUTION_H
#define _LIBCPP___RANDOM_DISCRETE_DISTRIBUTION_H
#include <__algorithm/upper_bound.h>
#include <__config>
#include <__random/is_valid.h>
#include <__random/uniform_real_distribution.h>
#include <cstddef>
#include <iosfwd>
#include <numeric>
#include <vector>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
template<class _IntType = int>
class _LIBCPP_TEMPLATE_VIS discrete_distribution
{
static_assert(__libcpp_random_is_valid_inttype<_IntType>::value, "IntType must be a supported integer type");
public:
// types
typedef _IntType result_type;
class _LIBCPP_TEMPLATE_VIS param_type
{
vector<double> __p_;
public:
typedef discrete_distribution distribution_type;
_LIBCPP_INLINE_VISIBILITY
param_type() {}
template<class _InputIterator>
_LIBCPP_INLINE_VISIBILITY
param_type(_InputIterator __f, _InputIterator __l)
: __p_(__f, __l) {__init();}
#ifndef _LIBCPP_CXX03_LANG
_LIBCPP_INLINE_VISIBILITY
param_type(initializer_list<double> __wl)
: __p_(__wl.begin(), __wl.end()) {__init();}
#endif // _LIBCPP_CXX03_LANG
template<class _UnaryOperation>
param_type(size_t __nw, double __xmin, double __xmax,
_UnaryOperation __fw);
vector<double> probabilities() const;
friend _LIBCPP_INLINE_VISIBILITY
bool operator==(const param_type& __x, const param_type& __y)
{return __x.__p_ == __y.__p_;}
friend _LIBCPP_INLINE_VISIBILITY
bool operator!=(const param_type& __x, const param_type& __y)
{return !(__x == __y);}
private:
void __init();
friend class discrete_distribution;
template <class _CharT, class _Traits, class _IT>
friend
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os,
const discrete_distribution<_IT>& __x);
template <class _CharT, class _Traits, class _IT>
friend
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __is,
discrete_distribution<_IT>& __x);
};
private:
param_type __p_;
public:
// constructor and reset functions
_LIBCPP_INLINE_VISIBILITY
discrete_distribution() {}
template<class _InputIterator>
_LIBCPP_INLINE_VISIBILITY
discrete_distribution(_InputIterator __f, _InputIterator __l)
: __p_(__f, __l) {}
#ifndef _LIBCPP_CXX03_LANG
_LIBCPP_INLINE_VISIBILITY
discrete_distribution(initializer_list<double> __wl)
: __p_(__wl) {}
#endif // _LIBCPP_CXX03_LANG
template<class _UnaryOperation>
_LIBCPP_INLINE_VISIBILITY
discrete_distribution(size_t __nw, double __xmin, double __xmax,
_UnaryOperation __fw)
: __p_(__nw, __xmin, __xmax, __fw) {}
_LIBCPP_INLINE_VISIBILITY
explicit discrete_distribution(const param_type& __p)
: __p_(__p) {}
_LIBCPP_INLINE_VISIBILITY
void reset() {}
// generating functions
template<class _URNG>
_LIBCPP_INLINE_VISIBILITY
result_type operator()(_URNG& __g)
{return (*this)(__g, __p_);}
template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
// property functions
_LIBCPP_INLINE_VISIBILITY
vector<double> probabilities() const {return __p_.probabilities();}
_LIBCPP_INLINE_VISIBILITY
param_type param() const {return __p_;}
_LIBCPP_INLINE_VISIBILITY
void param(const param_type& __p) {__p_ = __p;}
_LIBCPP_INLINE_VISIBILITY
result_type min() const {return 0;}
_LIBCPP_INLINE_VISIBILITY
result_type max() const {return __p_.__p_.size();}
friend _LIBCPP_INLINE_VISIBILITY
bool operator==(const discrete_distribution& __x,
const discrete_distribution& __y)
{return __x.__p_ == __y.__p_;}
friend _LIBCPP_INLINE_VISIBILITY
bool operator!=(const discrete_distribution& __x,
const discrete_distribution& __y)
{return !(__x == __y);}
template <class _CharT, class _Traits, class _IT>
friend
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os,
const discrete_distribution<_IT>& __x);
template <class _CharT, class _Traits, class _IT>
friend
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __is,
discrete_distribution<_IT>& __x);
};
template<class _IntType>
template<class _UnaryOperation>
discrete_distribution<_IntType>::param_type::param_type(size_t __nw,
double __xmin,
double __xmax,
_UnaryOperation __fw)
{
if (__nw > 1)
{
__p_.reserve(__nw - 1);
double __d = (__xmax - __xmin) / __nw;
double __d2 = __d / 2;
for (size_t __k = 0; __k < __nw; ++__k)
__p_.push_back(__fw(__xmin + __k * __d + __d2));
__init();
}
}
template<class _IntType>
void
discrete_distribution<_IntType>::param_type::__init()
{
if (!__p_.empty())
{
if (__p_.size() > 1)
{
double __s = _VSTD::accumulate(__p_.begin(), __p_.end(), 0.0);
for (vector<double>::iterator __i = __p_.begin(), __e = __p_.end(); __i < __e; ++__i)
*__i /= __s;
vector<double> __t(__p_.size() - 1);
_VSTD::partial_sum(__p_.begin(), __p_.end() - 1, __t.begin());
swap(__p_, __t);
}
else
{
__p_.clear();
__p_.shrink_to_fit();
}
}
}
template<class _IntType>
vector<double>
discrete_distribution<_IntType>::param_type::probabilities() const
{
size_t __n = __p_.size();
vector<double> __p(__n+1);
_VSTD::adjacent_difference(__p_.begin(), __p_.end(), __p.begin());
if (__n > 0)
__p[__n] = 1 - __p_[__n-1];
else
__p[0] = 1;
return __p;
}
template<class _IntType>
template<class _URNG>
_IntType
discrete_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
{
static_assert(__libcpp_random_is_valid_urng<_URNG>::value, "");
uniform_real_distribution<double> __gen;
return static_cast<_IntType>(
_VSTD::upper_bound(__p.__p_.begin(), __p.__p_.end(), __gen(__g)) -
__p.__p_.begin());
}
template <class _CharT, class _Traits, class _IT>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os,
const discrete_distribution<_IT>& __x)
{
__save_flags<_CharT, _Traits> __lx(__os);
typedef basic_ostream<_CharT, _Traits> _OStream;
__os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
_OStream::scientific);
_CharT __sp = __os.widen(' ');
__os.fill(__sp);
size_t __n = __x.__p_.__p_.size();
__os << __n;
for (size_t __i = 0; __i < __n; ++__i)
__os << __sp << __x.__p_.__p_[__i];
return __os;
}
template <class _CharT, class _Traits, class _IT>
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __is,
discrete_distribution<_IT>& __x)
{
__save_flags<_CharT, _Traits> __lx(__is);
typedef basic_istream<_CharT, _Traits> _Istream;
__is.flags(_Istream::dec | _Istream::skipws);
size_t __n;
__is >> __n;
vector<double> __p(__n);
for (size_t __i = 0; __i < __n; ++__i)
__is >> __p[__i];
if (!__is.fail())
swap(__x.__p_.__p_, __p);
return __is;
}
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___RANDOM_DISCRETE_DISTRIBUTION_H
|
