1 | /* -*- C++ -*- |
---|
2 | * |
---|
3 | * This file is a part of LEMON, a generic C++ optimization library |
---|
4 | * |
---|
5 | * Copyright (C) 2003-2006 |
---|
6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
8 | * |
---|
9 | * Permission to use, modify and distribute this software is granted |
---|
10 | * provided that this copyright notice appears in all copies. For |
---|
11 | * precise terms see the accompanying LICENSE file. |
---|
12 | * |
---|
13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
14 | * express or implied, and with no claim as to its suitability for any |
---|
15 | * purpose. |
---|
16 | * |
---|
17 | */ |
---|
18 | |
---|
19 | #ifndef LEMON_RANDOM_H |
---|
20 | #define LEMON_RANDOM_H |
---|
21 | |
---|
22 | #include <algorithm> |
---|
23 | #include <iterator> |
---|
24 | #include <vector> |
---|
25 | |
---|
26 | #include <ctime> |
---|
27 | #include <cmath> |
---|
28 | #include <cmath> |
---|
29 | |
---|
30 | ///\ingroup misc |
---|
31 | ///\file |
---|
32 | ///\brief Mersenne Twister random number generator |
---|
33 | /// |
---|
34 | ///\author Balazs Dezso |
---|
35 | |
---|
36 | namespace lemon { |
---|
37 | |
---|
38 | namespace _random_bits { |
---|
39 | |
---|
40 | template <typename _Word, int _bits = std::numeric_limits<_Word>::digits> |
---|
41 | struct RandomTraits {}; |
---|
42 | |
---|
43 | template <typename _Word> |
---|
44 | struct RandomTraits<_Word, 32> { |
---|
45 | |
---|
46 | typedef _Word Word; |
---|
47 | static const int bits = 32; |
---|
48 | |
---|
49 | static const int length = 624; |
---|
50 | static const int shift = 397; |
---|
51 | |
---|
52 | static const Word mul = 0x6c078965u; |
---|
53 | static const Word arrayInit = 0x012BD6AAu; |
---|
54 | static const Word arrayMul1 = 0x0019660Du; |
---|
55 | static const Word arrayMul2 = 0x5D588B65u; |
---|
56 | |
---|
57 | static const Word mask = 0x9908B0DFu; |
---|
58 | static const Word loMask = (1u << 31) - 1; |
---|
59 | static const Word hiMask = ~loMask; |
---|
60 | |
---|
61 | |
---|
62 | static Word tempering(Word rnd) { |
---|
63 | rnd ^= (rnd >> 11); |
---|
64 | rnd ^= (rnd << 7) & 0x9D2C5680u; |
---|
65 | rnd ^= (rnd << 15) & 0xEFC60000u; |
---|
66 | rnd ^= (rnd >> 18); |
---|
67 | return rnd; |
---|
68 | } |
---|
69 | |
---|
70 | }; |
---|
71 | |
---|
72 | template <typename _Word> |
---|
73 | struct RandomTraits<_Word, 64> { |
---|
74 | |
---|
75 | typedef _Word Word; |
---|
76 | static const int bits = 64; |
---|
77 | |
---|
78 | static const int length = 312; |
---|
79 | static const int shift = 156; |
---|
80 | |
---|
81 | static const Word mul = (Word)0x5851F42Du << 32 | (Word)0x4C957F2Du; |
---|
82 | static const Word arrayInit = (Word)0x00000000u << 32 |(Word)0x012BD6AAu; |
---|
83 | static const Word arrayMul1 = (Word)0x369DEA0Fu << 32 |(Word)0x31A53F85u; |
---|
84 | static const Word arrayMul2 = (Word)0x27BB2EE6u << 32 |(Word)0x87B0B0FDu; |
---|
85 | |
---|
86 | static const Word mask = (Word)0xB5026F5Au << 32 | (Word)0xA96619E9u; |
---|
87 | static const Word loMask = ((Word)1u << 31) - 1; |
---|
88 | static const Word hiMask = ~loMask; |
---|
89 | |
---|
90 | static Word tempering(Word rnd) { |
---|
91 | rnd ^= (rnd >> 29) & ((Word)0x55555555u << 32 | (Word)0x55555555u); |
---|
92 | rnd ^= (rnd << 17) & ((Word)0x71D67FFFu << 32 | (Word)0xEDA60000u); |
---|
93 | rnd ^= (rnd << 37) & ((Word)0xFFF7EEE0u << 32 | (Word)0x00000000u); |
---|
94 | rnd ^= (rnd >> 43); |
---|
95 | return rnd; |
---|
96 | } |
---|
97 | |
---|
98 | }; |
---|
99 | |
---|
100 | template <typename _Word> |
---|
101 | class RandomCore { |
---|
102 | public: |
---|
103 | |
---|
104 | typedef _Word Word; |
---|
105 | |
---|
106 | private: |
---|
107 | |
---|
108 | static const int bits = RandomTraits<Word>::bits; |
---|
109 | |
---|
110 | static const int length = RandomTraits<Word>::length; |
---|
111 | static const int shift = RandomTraits<Word>::shift; |
---|
112 | |
---|
113 | public: |
---|
114 | |
---|
115 | void initState() { |
---|
116 | static const Word seedArray[4] = { |
---|
117 | 0x12345u, 0x23456u, 0x34567u, 0x45678u |
---|
118 | }; |
---|
119 | |
---|
120 | initState(seedArray, seedArray + 4); |
---|
121 | } |
---|
122 | |
---|
123 | void initState(Word seed) { |
---|
124 | |
---|
125 | static const Word mul = RandomTraits<Word>::mul; |
---|
126 | |
---|
127 | current = state; |
---|
128 | |
---|
129 | Word *curr = state + length - 1; |
---|
130 | curr[0] = seed; --curr; |
---|
131 | for (int i = 1; i < length; ++i) { |
---|
132 | curr[0] = (mul * ( curr[1] ^ (curr[1] >> (bits - 2)) ) + i); |
---|
133 | --curr; |
---|
134 | } |
---|
135 | } |
---|
136 | |
---|
137 | template <typename Iterator> |
---|
138 | void initState(Iterator begin, Iterator end) { |
---|
139 | |
---|
140 | static const Word init = RandomTraits<Word>::arrayInit; |
---|
141 | static const Word mul1 = RandomTraits<Word>::arrayMul1; |
---|
142 | static const Word mul2 = RandomTraits<Word>::arrayMul2; |
---|
143 | |
---|
144 | |
---|
145 | Word *curr = state + length - 1; --curr; |
---|
146 | Iterator it = begin; int cnt = 0; |
---|
147 | int num; |
---|
148 | |
---|
149 | initState(init); |
---|
150 | |
---|
151 | num = length > end - begin ? length : end - begin; |
---|
152 | while (num--) { |
---|
153 | curr[0] = (curr[0] ^ ((curr[1] ^ (curr[1] >> (bits - 2))) * mul1)) |
---|
154 | + *it + cnt; |
---|
155 | ++it; ++cnt; |
---|
156 | if (it == end) { |
---|
157 | it = begin; cnt = 0; |
---|
158 | } |
---|
159 | if (curr == state) { |
---|
160 | curr = state + length - 1; curr[0] = state[0]; |
---|
161 | } |
---|
162 | --curr; |
---|
163 | } |
---|
164 | |
---|
165 | num = length - 1; cnt = length - (curr - state) - 1; |
---|
166 | while (num--) { |
---|
167 | curr[0] = (curr[0] ^ ((curr[1] ^ (curr[1] >> (bits - 2))) * mul2)) |
---|
168 | - cnt; |
---|
169 | --curr; ++cnt; |
---|
170 | if (curr == state) { |
---|
171 | curr = state + length - 1; curr[0] = state[0]; --curr; |
---|
172 | cnt = 1; |
---|
173 | } |
---|
174 | } |
---|
175 | |
---|
176 | state[length - 1] = (Word)1 << (bits - 1); |
---|
177 | } |
---|
178 | |
---|
179 | void copyState(const RandomCore& other) { |
---|
180 | std::copy(other.state, other.state + length, state); |
---|
181 | current = state + (other.current - other.state); |
---|
182 | } |
---|
183 | |
---|
184 | Word operator()() { |
---|
185 | if (current == state) fillState(); |
---|
186 | --current; |
---|
187 | Word rnd = *current; |
---|
188 | return RandomTraits<Word>::tempering(rnd); |
---|
189 | } |
---|
190 | |
---|
191 | private: |
---|
192 | |
---|
193 | |
---|
194 | void fillState() { |
---|
195 | static const Word mask[2] = { 0x0ul, RandomTraits<Word>::mask }; |
---|
196 | static const Word loMask = RandomTraits<Word>::loMask; |
---|
197 | static const Word hiMask = RandomTraits<Word>::hiMask; |
---|
198 | |
---|
199 | current = state + length; |
---|
200 | |
---|
201 | register Word *curr = state + length - 1; |
---|
202 | register long num; |
---|
203 | |
---|
204 | num = length - shift; |
---|
205 | while (num--) { |
---|
206 | curr[0] = (((curr[0] & hiMask) | (curr[-1] & loMask)) >> 1) ^ |
---|
207 | curr[- shift] ^ mask[curr[-1] & 1ul]; |
---|
208 | --curr; |
---|
209 | } |
---|
210 | num = shift - 1; |
---|
211 | while (num--) { |
---|
212 | curr[0] = (((curr[0] & hiMask) | (curr[-1] & loMask)) >> 1) ^ |
---|
213 | curr[length - shift] ^ mask[curr[-1] & 1ul]; |
---|
214 | --curr; |
---|
215 | } |
---|
216 | curr[0] = (((curr[0] & hiMask) | (curr[length - 1] & loMask)) >> 1) ^ |
---|
217 | curr[length - shift] ^ mask[curr[length - 1] & 1ul]; |
---|
218 | |
---|
219 | } |
---|
220 | |
---|
221 | |
---|
222 | Word *current; |
---|
223 | Word state[length]; |
---|
224 | |
---|
225 | }; |
---|
226 | |
---|
227 | |
---|
228 | template <typename Result, |
---|
229 | int shift = (std::numeric_limits<Result>::digits + 1) / 2> |
---|
230 | struct Masker { |
---|
231 | static Result mask(const Result& result) { |
---|
232 | return Masker<Result, (shift + 1) / 2>:: |
---|
233 | mask((Result)(result | (result >> shift))); |
---|
234 | } |
---|
235 | }; |
---|
236 | |
---|
237 | template <typename Result> |
---|
238 | struct Masker<Result, 1> { |
---|
239 | static Result mask(const Result& result) { |
---|
240 | return (Result)(result | (result >> 1)); |
---|
241 | } |
---|
242 | }; |
---|
243 | |
---|
244 | template <typename Result, typename Word, |
---|
245 | int rest = std::numeric_limits<Result>::digits, int shift = 0, |
---|
246 | bool last = rest <= std::numeric_limits<Word>::digits> |
---|
247 | struct IntConversion { |
---|
248 | static const int bits = std::numeric_limits<Word>::digits; |
---|
249 | |
---|
250 | static Result convert(RandomCore<Word>& rnd) { |
---|
251 | return (Result)(rnd() >> (bits - rest)) << shift; |
---|
252 | } |
---|
253 | |
---|
254 | }; |
---|
255 | |
---|
256 | template <typename Result, typename Word, int rest, int shift> |
---|
257 | struct IntConversion<Result, Word, rest, shift, false> { |
---|
258 | static const int bits = std::numeric_limits<Word>::digits; |
---|
259 | |
---|
260 | static Result convert(RandomCore<Word>& rnd) { |
---|
261 | return ((Result)rnd() << shift) | |
---|
262 | IntConversion<Result, Word, rest - bits, shift + bits>::convert(rnd); |
---|
263 | } |
---|
264 | }; |
---|
265 | |
---|
266 | |
---|
267 | template <typename Result, typename Word, |
---|
268 | bool one_word = std::numeric_limits<Word>::digits < |
---|
269 | std::numeric_limits<Result>::digits> |
---|
270 | struct Mapping { |
---|
271 | static Result map(RandomCore<Word>& rnd, const Result& bound) { |
---|
272 | Word max = (Word)(bound - 1); |
---|
273 | Result mask = Masker<Result>::mask(bound - 1); |
---|
274 | Result num; |
---|
275 | do { |
---|
276 | num = IntConversion<Result, Word>::convert(rnd) & mask; |
---|
277 | } while (num > max); |
---|
278 | return num; |
---|
279 | } |
---|
280 | }; |
---|
281 | |
---|
282 | template <typename Result, typename Word> |
---|
283 | struct Mapping<Result, Word, false> { |
---|
284 | static Result map(RandomCore<Word>& rnd, const Result& bound) { |
---|
285 | Word max = (Word)(bound - 1); |
---|
286 | Word mask = Masker<Word, (std::numeric_limits<Result>::digits + 1) / 2> |
---|
287 | ::mask(max); |
---|
288 | Word num; |
---|
289 | do { |
---|
290 | num = rnd() & mask; |
---|
291 | } while (num > max); |
---|
292 | return num; |
---|
293 | } |
---|
294 | }; |
---|
295 | |
---|
296 | template <typename Result, int exp, bool pos = (exp >= 0)> |
---|
297 | struct ShiftMultiplier { |
---|
298 | static const Result multiplier() { |
---|
299 | Result res = ShiftMultiplier<Result, exp / 2>::multiplier(); |
---|
300 | res *= res; |
---|
301 | if ((exp & 1) == 1) res *= (Result)2.0; |
---|
302 | return res; |
---|
303 | } |
---|
304 | }; |
---|
305 | |
---|
306 | template <typename Result, int exp> |
---|
307 | struct ShiftMultiplier<Result, exp, false> { |
---|
308 | static const Result multiplier() { |
---|
309 | Result res = ShiftMultiplier<Result, exp / 2>::multiplier(); |
---|
310 | res *= res; |
---|
311 | if ((exp & 1) == 1) res *= (Result)0.5; |
---|
312 | return res; |
---|
313 | } |
---|
314 | }; |
---|
315 | |
---|
316 | template <typename Result> |
---|
317 | struct ShiftMultiplier<Result, 0, true> { |
---|
318 | static const Result multiplier() { |
---|
319 | return (Result)1.0; |
---|
320 | } |
---|
321 | }; |
---|
322 | |
---|
323 | template <typename Result> |
---|
324 | struct ShiftMultiplier<Result, -20, true> { |
---|
325 | static const Result multiplier() { |
---|
326 | return (Result)(1.0/1048576.0); |
---|
327 | } |
---|
328 | }; |
---|
329 | |
---|
330 | template <typename Result> |
---|
331 | struct ShiftMultiplier<Result, -32, true> { |
---|
332 | static const Result multiplier() { |
---|
333 | return (Result)(1.0/424967296.0); |
---|
334 | } |
---|
335 | }; |
---|
336 | |
---|
337 | template <typename Result> |
---|
338 | struct ShiftMultiplier<Result, -53, true> { |
---|
339 | static const Result multiplier() { |
---|
340 | return (Result)(1.0/9007199254740992.0); |
---|
341 | } |
---|
342 | }; |
---|
343 | |
---|
344 | template <typename Result> |
---|
345 | struct ShiftMultiplier<Result, -64, true> { |
---|
346 | static const Result multiplier() { |
---|
347 | return (Result)(1.0/18446744073709551616.0); |
---|
348 | } |
---|
349 | }; |
---|
350 | |
---|
351 | template <typename Result, int exp> |
---|
352 | struct Shifting { |
---|
353 | static Result shift(const Result& result) { |
---|
354 | return result * ShiftMultiplier<Result, exp>::multiplier(); |
---|
355 | } |
---|
356 | }; |
---|
357 | |
---|
358 | template <typename Result, typename Word, |
---|
359 | int rest = std::numeric_limits<Result>::digits, int shift = 0, |
---|
360 | bool last = rest <= std::numeric_limits<Word>::digits> |
---|
361 | struct RealConversion{ |
---|
362 | static const int bits = std::numeric_limits<Word>::digits; |
---|
363 | |
---|
364 | static Result convert(RandomCore<Word>& rnd) { |
---|
365 | return Shifting<Result, - shift - rest>:: |
---|
366 | shift((Result)(rnd() >> (bits - rest))); |
---|
367 | } |
---|
368 | }; |
---|
369 | |
---|
370 | template <typename Result, typename Word, int rest, int shift> |
---|
371 | struct RealConversion<Result, Word, rest, shift, false> { |
---|
372 | static const int bits = std::numeric_limits<Word>::digits; |
---|
373 | |
---|
374 | static Result convert(RandomCore<Word>& rnd) { |
---|
375 | return Shifting<Result, - shift - bits>::shift((Result)rnd()) + |
---|
376 | RealConversion<Result, Word, rest-bits, shift + bits>::convert(rnd); |
---|
377 | } |
---|
378 | }; |
---|
379 | |
---|
380 | template <typename Result, typename Word> |
---|
381 | struct Initializer { |
---|
382 | |
---|
383 | template <typename Iterator> |
---|
384 | static void init(RandomCore<Word>& rnd, Iterator begin, Iterator end) { |
---|
385 | std::vector<Word> ws; |
---|
386 | for (Iterator it = begin; it != end; ++it) { |
---|
387 | ws.push_back((Word)*it); |
---|
388 | } |
---|
389 | rnd.initState(ws.begin(), ws.end()); |
---|
390 | } |
---|
391 | |
---|
392 | template <typename Iterator> |
---|
393 | static void init(RandomCore<Word>& rnd, Result seed) { |
---|
394 | rnd.initState(seed); |
---|
395 | } |
---|
396 | }; |
---|
397 | |
---|
398 | template <typename Word> |
---|
399 | struct BoolConversion { |
---|
400 | static bool convert(RandomCore<Word>& rnd) { |
---|
401 | return (rnd() & 1) == 1; |
---|
402 | } |
---|
403 | }; |
---|
404 | |
---|
405 | } |
---|
406 | |
---|
407 | /// \ingroup misc |
---|
408 | /// |
---|
409 | /// \brief Mersenne Twister random number generator |
---|
410 | /// |
---|
411 | /// The Mersenne Twister is a twisted generalized feedback |
---|
412 | /// shift-register generator of Matsumoto and Nishimura. The period |
---|
413 | /// of this generator is \f$ 2^{19937} - 1 \f$ and it is |
---|
414 | /// equi-distributed in 623 dimensions for 32-bit numbers. The time |
---|
415 | /// performance of this generator is comparable to the commonly used |
---|
416 | /// generators. |
---|
417 | /// |
---|
418 | /// This implementation is specialized for both 32-bit and 64-bit |
---|
419 | /// architectures. The generators differ sligthly in the |
---|
420 | /// initialization and generation phase so they produce two |
---|
421 | /// completly different sequences. |
---|
422 | /// |
---|
423 | /// The generator gives back random numbers of serveral types. To |
---|
424 | /// get a random number from a range of a floating point type you |
---|
425 | /// can use one form of the \c operator() or the \c real() member |
---|
426 | /// function. If you want to get random number from the {0, 1, ..., |
---|
427 | /// n-1} integer range use the \c operator[] or the \c integer() |
---|
428 | /// method. And to get random number from the whole range of an |
---|
429 | /// integer type you can use the argumentless \c integer() or \c |
---|
430 | /// uinteger() functions. After all you can get random bool with |
---|
431 | /// equal chance of true and false or given probability of true |
---|
432 | /// result with the \c boolean() member functions. |
---|
433 | /// |
---|
434 | ///\code |
---|
435 | /// // The commented code is identical to the other |
---|
436 | /// double a = rnd(); // [0.0, 1.0) |
---|
437 | /// // double a = rnd.real(); // [0.0, 1.0) |
---|
438 | /// double b = rnd(100.0); // [0.0, 100.0) |
---|
439 | /// // double b = rnd.real(100.0); // [0.0, 100.0) |
---|
440 | /// double c = rnd(1.0, 2.0); // [1.0, 2.0) |
---|
441 | /// // double c = rnd.real(1.0, 2.0); // [1.0, 2.0) |
---|
442 | /// int d = rnd[100000]; // 0..99999 |
---|
443 | /// // int d = rnd.integer(100000); // 0..99999 |
---|
444 | /// int e = rnd[6] + 1; // 1..6 |
---|
445 | /// // int e = rnd.integer(1, 1 + 6); // 1..6 |
---|
446 | /// int b = rnd.uinteger<int>(); // 0 .. 2^31 - 1 |
---|
447 | /// int c = rnd.integer<int>(); // - 2^31 .. 2^31 - 1 |
---|
448 | /// bool g = rnd.boolean(); // P(g = true) = 0.5 |
---|
449 | /// bool h = rnd.boolean(0.8); // P(h = true) = 0.8 |
---|
450 | ///\endcode |
---|
451 | /// |
---|
452 | /// The lemon provides a global instance of the random number |
---|
453 | /// generator which name is \ref lemon::rnd "rnd". Usually it is a |
---|
454 | /// good programming convenience to use this global generator to get |
---|
455 | /// random numbers. |
---|
456 | /// |
---|
457 | /// \author Balazs Dezso |
---|
458 | class Random { |
---|
459 | private: |
---|
460 | |
---|
461 | // architecture word |
---|
462 | typedef unsigned long Word; |
---|
463 | |
---|
464 | _random_bits::RandomCore<Word> core; |
---|
465 | |
---|
466 | public: |
---|
467 | |
---|
468 | /// \brief Constructor |
---|
469 | /// |
---|
470 | /// Constructor with constant seeding. |
---|
471 | Random() { core.initState(); } |
---|
472 | |
---|
473 | /// \brief Constructor |
---|
474 | /// |
---|
475 | /// Constructor with seed. The current number type will be converted |
---|
476 | /// to the architecture word type. |
---|
477 | template <typename Number> |
---|
478 | Random(Number seed) { |
---|
479 | _random_bits::Initializer<Number, Word>::init(core, seed); |
---|
480 | } |
---|
481 | |
---|
482 | /// \brief Constructor |
---|
483 | /// |
---|
484 | /// Constructor with array seeding. The given range should contain |
---|
485 | /// any number type and the numbers will be converted to the |
---|
486 | /// architecture word type. |
---|
487 | template <typename Iterator> |
---|
488 | Random(Iterator begin, Iterator end) { |
---|
489 | typedef typename std::iterator_traits<Iterator>::value_type Number; |
---|
490 | _random_bits::Initializer<Number, Word>::init(core, begin, end); |
---|
491 | } |
---|
492 | |
---|
493 | /// \brief Copy constructor |
---|
494 | /// |
---|
495 | /// Copy constructor. The generated sequence will be identical to |
---|
496 | /// the other sequence. It can be used to save the current state |
---|
497 | /// of the generator and later use it to generate the same |
---|
498 | /// sequence. |
---|
499 | Random(const Random& other) { |
---|
500 | core.copyState(other.core); |
---|
501 | } |
---|
502 | |
---|
503 | /// \brief Assign operator |
---|
504 | /// |
---|
505 | /// Assign operator. The generated sequence will be identical to |
---|
506 | /// the other sequence. It can be used to save the current state |
---|
507 | /// of the generator and later use it to generate the same |
---|
508 | /// sequence. |
---|
509 | Random& operator=(const Random& other) { |
---|
510 | if (&other != this) { |
---|
511 | core.copyState(other.core); |
---|
512 | } |
---|
513 | return *this; |
---|
514 | } |
---|
515 | |
---|
516 | /// \brief Returns a random real number from the range [0, 1) |
---|
517 | /// |
---|
518 | /// It returns a random real number from the range [0, 1). The |
---|
519 | /// default Number type is double. |
---|
520 | template <typename Number> |
---|
521 | Number real() { |
---|
522 | return _random_bits::RealConversion<Number, Word>::convert(core); |
---|
523 | } |
---|
524 | |
---|
525 | double real() { |
---|
526 | return real<double>(); |
---|
527 | } |
---|
528 | |
---|
529 | /// \brief Returns a random real number the range [0, b) |
---|
530 | /// |
---|
531 | /// It returns a random real number from the range [0, b). |
---|
532 | template <typename Number> |
---|
533 | Number real(Number b) { |
---|
534 | return real<Number>() * b; |
---|
535 | } |
---|
536 | |
---|
537 | /// \brief Returns a random real number from the range [a, b) |
---|
538 | /// |
---|
539 | /// It returns a random real number from the range [a, b). |
---|
540 | template <typename Number> |
---|
541 | Number real(Number a, Number b) { |
---|
542 | return real<Number>() * (b - a) + a; |
---|
543 | } |
---|
544 | |
---|
545 | /// \brief Returns a random real number from the range [0, 1) |
---|
546 | /// |
---|
547 | /// It returns a random double from the range [0, 1). |
---|
548 | double operator()() { |
---|
549 | return real<double>(); |
---|
550 | } |
---|
551 | |
---|
552 | /// \brief Returns a random real number from the range [0, b) |
---|
553 | /// |
---|
554 | /// It returns a random real number from the range [0, b). |
---|
555 | template <typename Number> |
---|
556 | Number operator()(Number b) { |
---|
557 | return real<Number>() * b; |
---|
558 | } |
---|
559 | |
---|
560 | /// \brief Returns a random real number from the range [a, b) |
---|
561 | /// |
---|
562 | /// It returns a random real number from the range [a, b). |
---|
563 | template <typename Number> |
---|
564 | Number operator()(Number a, Number b) { |
---|
565 | return real<Number>() * (b - a) + a; |
---|
566 | } |
---|
567 | |
---|
568 | /// \brief Returns a random integer from a range |
---|
569 | /// |
---|
570 | /// It returns a random integer from the range {0, 1, ..., b - 1}. |
---|
571 | template <typename Number> |
---|
572 | Number integer(Number b) { |
---|
573 | return _random_bits::Mapping<Number, Word>::map(core, b); |
---|
574 | } |
---|
575 | |
---|
576 | /// \brief Returns a random integer from a range |
---|
577 | /// |
---|
578 | /// It returns a random integer from the range {a, a + 1, ..., b - 1}. |
---|
579 | template <typename Number> |
---|
580 | Number integer(Number a, Number b) { |
---|
581 | return _random_bits::Mapping<Number, Word>::map(core, b - a) + a; |
---|
582 | } |
---|
583 | |
---|
584 | /// \brief Returns a random integer from a range |
---|
585 | /// |
---|
586 | /// It returns a random integer from the range {0, 1, ..., b - 1}. |
---|
587 | template <typename Number> |
---|
588 | Number operator[](Number b) { |
---|
589 | return _random_bits::Mapping<Number, Word>::map(core, b); |
---|
590 | } |
---|
591 | |
---|
592 | /// \brief Returns a random non-negative integer |
---|
593 | /// |
---|
594 | /// It returns a random non-negative integer uniformly from the |
---|
595 | /// whole range of the current \c Number type. The default result |
---|
596 | /// type of this function is unsigned int. |
---|
597 | template <typename Number> |
---|
598 | Number uinteger() { |
---|
599 | return _random_bits::IntConversion<Number, Word>::convert(core); |
---|
600 | } |
---|
601 | |
---|
602 | unsigned int uinteger() { |
---|
603 | return uinteger<unsigned int>(); |
---|
604 | } |
---|
605 | |
---|
606 | /// \brief Returns a random integer |
---|
607 | /// |
---|
608 | /// It returns a random integer uniformly from the whole range of |
---|
609 | /// the current \c Number type. The default result type of this |
---|
610 | /// function is int. |
---|
611 | template <typename Number> |
---|
612 | Number integer() { |
---|
613 | static const int nb = std::numeric_limits<Number>::digits + |
---|
614 | (std::numeric_limits<Number>::is_signed ? 1 : 0); |
---|
615 | return _random_bits::IntConversion<Number, Word, nb>::convert(core); |
---|
616 | } |
---|
617 | |
---|
618 | int integer() { |
---|
619 | return integer<int>(); |
---|
620 | } |
---|
621 | |
---|
622 | /// \brief Returns a random bool |
---|
623 | /// |
---|
624 | /// It returns a random bool |
---|
625 | bool boolean() { |
---|
626 | return _random_bits::BoolConversion<Word>::convert(core); |
---|
627 | } |
---|
628 | |
---|
629 | /// \brief Returns a random bool |
---|
630 | /// |
---|
631 | /// It returns a random bool with given probability of true result |
---|
632 | bool boolean(double p) { |
---|
633 | return operator()() < p; |
---|
634 | } |
---|
635 | |
---|
636 | }; |
---|
637 | |
---|
638 | |
---|
639 | extern Random rnd; |
---|
640 | |
---|
641 | } |
---|
642 | |
---|
643 | #endif |
---|