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at develop
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- *//* * Main authors: * Christian Schulte <schulte@gecode.org> * Mikael Lagerkvist <lagerkvist@gecode.org> * * Copyright: * Christian Schulte, 2005 * Mikael Lagerkvist, 2005 * * This file is part of Gecode, the generic constraint * development environment: * http://www.gecode.org * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * */
#include <algorithm>
namespace Gecode { namespace Support {
/** \brief Template for linear congruential generators * * This class template defines a simple class for linear * congruential generators. * * \ingroup FuncSupport */ template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> class LinearCongruentialGenerator { private: /// The maximum size of random numbers generated. static const unsigned int max = 1UL<<31; /// Current seed value unsigned int s; /// Returns a random integer from the interval \f$[0\ldots n)\f$ unsigned int u(unsigned int n); /// Returns a random integer from the interval \f$[0\ldots n)\f$ unsigned long long int ull(unsigned long long int n); public: /// Set the current seed to \a s void seed(unsigned int s); /// Construct the generator instance with seed \a s LinearCongruentialGenerator(unsigned int s = 1); /// Return current seed unsigned int seed(void) const; /// Generate next number in series unsigned int next(void); /// Returns a random integer from the interval \f$[0\ldots n)\f$ template<class Type> Type operator ()(Type n); /// Returns a random integer from the interval \f$[0\ldots n)\f$ int operator ()(int n); /// Returns a random integer from the interval \f$[0\ldots n)\f$ unsigned int operator ()(unsigned int n); /// Returns a random integer from the interval \f$[0\ldots n)\f$ long long int operator ()(long long int n); /// Report size occupied size_t size(void) const; };
template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline unsigned int LinearCongruentialGenerator<m,a,q,r>::next(void) { s = a*(s%q) - r*(s/q); unsigned int res = s; if (s==0) s = 1; return res; } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline void LinearCongruentialGenerator<m,a,q,r>::seed(unsigned int _s) { s = _s % m; if (s == 0) s = 1; } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline LinearCongruentialGenerator<m,a,q,r>:: LinearCongruentialGenerator(unsigned int _s) { seed(_s); } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline unsigned int LinearCongruentialGenerator<m,a,q,r>::seed(void) const { return s; }
template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline unsigned int LinearCongruentialGenerator<m,a,q,r>::u(unsigned int n) { unsigned int x1 = next() & ((1U<<16)-1U); unsigned int x2 = next() & ((1U<<16)-1U); if (n < 2) return 0; double d = static_cast<double>(((x1<<16) | x2) % max) / max; unsigned int val = static_cast<unsigned int>(n * d); return (val < n) ? val : (n-1); } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline unsigned long long int LinearCongruentialGenerator<m,a,q,r>::ull(unsigned long long int n) { if (n <= UINT_MAX) return u(static_cast<unsigned int>(n)); unsigned long long int x1 = next() & ((1LLU<<16)-1LLU); unsigned long long int x2 = next() & ((1LLU<<16)-1LLU); unsigned long long int x3 = next() & ((1LLU<<16)-1LLU); unsigned long long int x4 = next() & ((1LLU<<16)-1LLU); if (n < 2) return 0; return ((x1 << 48) | (x2 << 32) | (x3 << 16) | x4) % n; }
template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> template<class Type> forceinline Type LinearCongruentialGenerator<m,a,q,r>::operator ()(Type n) { return static_cast<Type>(ull(static_cast<unsigned long long int>(n))); } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline unsigned int LinearCongruentialGenerator<m,a,q,r>::operator ()(unsigned int n) { return u(n); } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline int LinearCongruentialGenerator<m,a,q,r>::operator ()(int n) { return (n < 0) ? 0 : static_cast<int>(u(static_cast<unsigned int>(n))); } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline long long int LinearCongruentialGenerator<m,a,q,r>::operator ()(long long int n) { return (n < 0) ? 0 : static_cast<long long int> (ull(static_cast<unsigned long long int>(n))); } template<unsigned int m, unsigned int a, unsigned int q, unsigned int r> forceinline size_t LinearCongruentialGenerator<m,a,q,r>::size(void) const { return sizeof(LinearCongruentialGenerator<m,a,q,r>); }
/** \brief Default values for linear congruential generator * * While this pseudo-random number generator is not a good source of * randomness, it is still an acceptable choice for many * applications. The choice of values is taken from D. E. Knuth, * The Art of Computer Programming, Vol 2, Seminumerical Algorithms, * 3rd edition. * * \ingroup FuncSupport */ typedef LinearCongruentialGenerator<2147483647, 48271, 44488, 3399> RandomGenerator;
}}
// STATISTICS: support-any