| // -*- C++ -*- |
| |
| // Copyright (C) 2005-2022 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the terms |
| // of the GNU General Public License as published by the Free Software |
| // Foundation; either version 3, or (at your option) any later |
| // version. |
| |
| // This library is distributed in the hope that it will be useful, but |
| // WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| // General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License along |
| // with this library; see the file COPYING3. If not see |
| // <http://www.gnu.org/licenses/>. |
| |
| |
| // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL. |
| |
| // Permission to use, copy, modify, sell, and distribute this software |
| // is hereby granted without fee, provided that the above copyright |
| // notice appears in all copies, and that both that copyright notice |
| // and this permission notice appear in supporting documentation. None |
| // of the above authors, nor IBM Haifa Research Laboratories, make any |
| // representation about the suitability of this software for any |
| // purpose. It is provided "as is" without express or implied |
| // warranty. |
| |
| /** |
| * @file testsuite_rng.h |
| */ |
| |
| #ifndef _GLIBCXX_TESTSUITE_RNG_H |
| #define _GLIBCXX_TESTSUITE_RNG_H |
| |
| #include <ctime> |
| #include <climits> |
| #include <debug/debug.h> |
| #include <tr1/random> |
| |
| namespace __gnu_pbds |
| { |
| namespace test |
| { |
| class twister_rand_gen |
| { |
| public: |
| twister_rand_gen(unsigned int seed = |
| static_cast<unsigned int>(std::time(0))) |
| : m_base_generator(seed) |
| { |
| // Do nothing. |
| } |
| |
| void |
| init(unsigned int seed) |
| { m_base_generator.seed(seed); } |
| |
| static unsigned int |
| get_time_determined_seed() |
| { return(static_cast<unsigned int>(std::time(0))); } |
| |
| unsigned long |
| get_unsigned_long(unsigned long min = 0, |
| unsigned long max = UINT_MAX - 1) |
| { |
| _GLIBCXX_DEBUG_ASSERT(max >= min); |
| const double prob = get_prob(); |
| const unsigned long r = (unsigned long)((max - min + 1) * prob) + min; |
| _GLIBCXX_DEBUG_ASSERT(r <= max); |
| return r; |
| } |
| |
| double |
| get_prob() |
| { |
| const double min = m_base_generator.min(); |
| const double max = m_base_generator.max(); |
| const double range = static_cast<double>(max - min); |
| const double res = static_cast<double>(m_base_generator() - min); |
| const double ret = res / range; |
| _GLIBCXX_DEBUG_ASSERT(ret >= 0 && ret <= 1); |
| return ret; |
| } |
| |
| private: |
| typedef std::tr1::mt19937 base_generator_t; |
| |
| base_generator_t m_base_generator; |
| }; |
| } // namespace test |
| } // namespace __gnu_pbds |
| |
| #endif // #ifndef _GLIBCXX_TESTSUITE_RNG_H |