relax.hh
Go to the documentation of this file.00001 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */ 00002 /* 00003 * Main authors: 00004 * Christian Schulte <schulte@gecode.org> 00005 * 00006 * Copyright: 00007 * Christian Schulte, 2016 00008 * 00009 * Last modified: 00010 * $Date: 2017-03-01 06:50:42 +0100 (Wed, 01 Mar 2017) $ by $Author: schulte $ 00011 * $Revision: 15542 $ 00012 * 00013 * This file is part of Gecode, the generic constraint 00014 * development environment: 00015 * http://www.gecode.org 00016 * 00017 * Permission is hereby granted, free of charge, to any person obtaining 00018 * a copy of this software and associated documentation files (the 00019 * "Software"), to deal in the Software without restriction, including 00020 * without limitation the rights to use, copy, modify, merge, publish, 00021 * distribute, sublicense, and/or sell copies of the Software, and to 00022 * permit persons to whom the Software is furnished to do so, subject to 00023 * the following conditions: 00024 * 00025 * The above copyright notice and this permission notice shall be 00026 * included in all copies or substantial portions of the Software. 00027 * 00028 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 00029 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 00030 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 00031 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 00032 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 00033 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 00034 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 00035 * 00036 */ 00037 00038 #ifndef __GECODE_SEARCH_RELAX_HH__ 00039 #define __GECODE_SEARCH_RELAX_HH__ 00040 00041 #include <gecode/kernel.hh> 00042 #include <gecode/search.hh> 00043 00044 namespace Gecode { namespace Search { 00045 00047 template<class VarArgs, class Post> 00048 forceinline void 00049 relax(Home home, const VarArgs& x, const VarArgs& sx, Rnd r, 00050 double p, Post& post); 00051 00052 00053 template<class VarArgs, class Post> 00054 forceinline void 00055 relax(Home home, const VarArgs& x, const VarArgs& sx, Rnd r, 00056 double p, Post& post) { 00057 if (home.failed()) 00058 return; 00059 Region reg(home); 00060 // Which variables to assign 00061 Support::BitSet<Region> ax(reg, static_cast<unsigned int>(x.size())); 00062 // Select randomly with probability p to relax value 00063 for (int i=x.size(); i--; ) 00064 if (r(UINT_MAX) >= 00065 static_cast<unsigned int>(p * static_cast<double>(UINT_MAX))) 00066 ax.set(static_cast<unsigned int>(i)); 00067 if (ax.all()) 00068 // Choose one variable uniformly and unset it 00069 ax.clear(r(static_cast<unsigned int>(x.size()))); 00070 for (Iter::Values::BitSet<Support::BitSet<Region> > i(ax); i(); ++i) 00071 if (post(home, x[i.val()], sx[i.val()]) != ES_OK) { 00072 home.failed(); 00073 return; 00074 } 00075 } 00076 00077 }} 00078 00079 #endif 00080 00081 // STATISTICS: search-other