hull.cpp
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00001 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */ 00002 /* 00003 * Main authors: 00004 * Guido Tack <tack@gecode.org> 00005 * Christian Schulte <schulte@gecode.org> 00006 * 00007 * Contributing authors: 00008 * Gabor Szokoli <szokoli@gecode.org> 00009 * 00010 * Copyright: 00011 * Guido Tack, 2004 00012 * Christian Schulte, 2004 00013 * Gabor Szokoli, 2004 00014 * 00015 * Last modified: 00016 * $Date: 2010-03-03 17:32:21 +0100 (Wed, 03 Mar 2010) $ by $Author: schulte $ 00017 * $Revision: 10364 $ 00018 * 00019 * This file is part of Gecode, the generic constraint 00020 * development environment: 00021 * http://www.gecode.org 00022 * 00023 * Permission is hereby granted, free of charge, to any person obtaining 00024 * a copy of this software and associated documentation files (the 00025 * "Software"), to deal in the Software without restriction, including 00026 * without limitation the rights to use, copy, modify, merge, publish, 00027 * distribute, sublicense, and/or sell copies of the Software, and to 00028 * permit persons to whom the Software is furnished to do so, subject to 00029 * the following conditions: 00030 * 00031 * The above copyright notice and this permission notice shall be 00032 * included in all copies or substantial portions of the Software. 00033 * 00034 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 00035 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 00036 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 00037 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 00038 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 00039 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 00040 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 00041 * 00042 */ 00043 00044 #include <gecode/set/convex.hh> 00045 00046 namespace Gecode { namespace Set { namespace Convex { 00047 00048 Actor* 00049 ConvexHull::copy(Space& home, bool share) { 00050 return new (home) ConvexHull(home,share,*this); 00051 } 00052 00053 ExecStatus 00054 ConvexHull::propagate(Space& home, const ModEventDelta&) { 00055 //x1 is the convex hull of x0 00056 00057 GECODE_ME_CHECK( x1.cardMin(home,x0.cardMin()) ); 00058 GECODE_ME_CHECK( x0.cardMax(home,x1.cardMax()) ); 00059 00060 do { 00061 00062 //intersect x1 with (x0.lubMin(),x0.lubMax()) 00063 //This empties x1 if x0.ub is empty. twice. 00064 GECODE_ME_CHECK( x1.exclude(home,Limits::min, 00065 x0.lubMin()-1) ); 00066 GECODE_ME_CHECK( x1.exclude(home,x0.lubMax()+1, 00067 Limits::max) ); 00068 00069 int minElement = std::min(x1.glbMin(),x0.glbMin()); 00070 int maxElement = std::max(x1.glbMax(),x0.glbMax()); 00071 00072 if (minElement<maxElement) { 00073 GECODE_ME_CHECK( x1.include(home, minElement, maxElement)); 00074 } 00075 00076 unsigned int cardMin = x1.cardMin(); 00077 00078 LubRanges<SetView> ubRangeIt(x1); 00079 Iter::Ranges::Cache< LubRanges<SetView> > ubRangeItC(ubRangeIt); 00080 for (;ubRangeItC();++ubRangeItC){ 00081 if (ubRangeItC.width() < cardMin 00082 || ubRangeItC.min() > minElement //No need to test for empty lb. 00083 || ubRangeItC.max() < maxElement 00084 ) { 00085 GECODE_ME_CHECK( x1.exclude(home, 00086 ubRangeItC.min(), ubRangeItC.max()) ); 00087 } 00088 } 00089 00090 LubRanges<SetView> ubRangeIt2(x1); 00091 GECODE_ME_CHECK(x0.intersectI(home,ubRangeIt2) ); 00092 00093 if (x1.lubMin()!=BndSet::MIN_OF_EMPTY) { 00094 if(x1.lubMin()==x1.glbMin()) { 00095 GECODE_ME_CHECK(x0.include(home,x1.lubMin())); 00096 } 00097 if(x1.lubMax()==x1.glbMax()) { 00098 GECODE_ME_CHECK(x0.include(home,x1.lubMax())); 00099 } 00100 } 00101 } while(x0.assigned()&&!x1.assigned()); 00102 00103 //If x0 is assigned, x1 should be too. 00104 assert(x1.assigned() || !x0.assigned()); 00105 00106 if (x1.assigned()) { 00107 return home.ES_SUBSUMED(*this); 00108 } 00109 00110 return ES_NOFIX; 00111 } 00112 00113 }}} 00114 00115 // STATISTICS: set-prop