001package org.cpsolver.coursett.criteria.placement; 002 003import java.util.Collection; 004import java.util.Map; 005import java.util.Set; 006 007import org.cpsolver.coursett.model.Lecture; 008import org.cpsolver.coursett.model.Placement; 009import org.cpsolver.ifs.assignment.Assignment; 010import org.cpsolver.ifs.extension.ConflictStatistics; 011import org.cpsolver.ifs.extension.Extension; 012import org.cpsolver.ifs.solution.Solution; 013import org.cpsolver.ifs.solution.SolutionListener; 014import org.cpsolver.ifs.solver.Solver; 015 016 017/** 018 * Hard conflicts weighted by the conflict-based statistics (past occurrences). 019 * <br> 020 * 021 * @version CourseTT 1.3 (University Course Timetabling)<br> 022 * Copyright (C) 2006 - 2014 Tomáš Müller<br> 023 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 024 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 025 * <br> 026 * This library is free software; you can redistribute it and/or modify 027 * it under the terms of the GNU Lesser General Public License as 028 * published by the Free Software Foundation; either version 3 of the 029 * License, or (at your option) any later version. <br> 030 * <br> 031 * This library is distributed in the hope that it will be useful, but 032 * WITHOUT ANY WARRANTY; without even the implied warranty of 033 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 034 * Lesser General Public License for more details. <br> 035 * <br> 036 * You should have received a copy of the GNU Lesser General Public 037 * License along with this library; if not see 038 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 039 */ 040public class WeightedHardConflicts extends PlacementSelectionCriterion implements SolutionListener<Lecture, Placement> { 041 protected ConflictStatistics<Lecture, Placement> iStat = null; 042 043 @Override 044 public boolean init(Solver<Lecture, Placement> solver) { 045 super.init(solver); 046 for (Extension<Lecture, Placement> extension : solver.getExtensions()) { 047 if (ConflictStatistics.class.isInstance(extension)) 048 iStat = (ConflictStatistics<Lecture, Placement>) extension; 049 } 050 solver.currentSolution().addSolutionListener(this); 051 return true; 052 } 053 054 @Override 055 public String getPlacementSelectionWeightName() { 056 return "Placement.NrConflictsWeight"; 057 } 058 059 @Override 060 public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) { 061 if (iStat != null && conflicts != null && !conflicts.isEmpty()) { 062 return iStat.countRemovals(((IterationContext)getContext(assignment)).getIteration(), conflicts, value); 063 } else { 064 return 0.0; 065 } 066 } 067 068 @Override 069 public double getPlacementSelectionWeightDefault(int level) { 070 return (level == 0 ? 3.0 : 0.0); 071 } 072 073 @Override 074 public void solutionUpdated(Solution<Lecture, Placement> solution) { 075 ((IterationContext)getContext(solution.getAssignment())).setIteration(solution.getIteration()); 076 } 077 078 @Override 079 public void getInfo(Solution<Lecture, Placement> solution, Map<String, String> info) { 080 } 081 082 @Override 083 public void getInfo(Solution<Lecture, Placement> solution, Map<String, String> info, Collection<Lecture> variables) { 084 } 085 086 @Override 087 public void bestCleared(Solution<Lecture, Placement> solution) { 088 ((IterationContext)getContext(solution.getAssignment())).setIteration(solution.getIteration()); 089 } 090 091 @Override 092 public void bestSaved(Solution<Lecture, Placement> solution) { 093 ((IterationContext)getContext(solution.getAssignment())).setIteration(solution.getIteration()); 094 } 095 096 @Override 097 public void bestRestored(Solution<Lecture, Placement> solution) { 098 ((IterationContext)getContext(solution.getAssignment())).setIteration(solution.getIteration()); 099 } 100 101 @Override 102 public ValueContext createAssignmentContext(Assignment<Lecture, Placement> assignment) { 103 return new IterationContext(assignment); 104 } 105 106 public class IterationContext extends ValueContext { 107 protected long iIteration = 0; 108 109 protected IterationContext(Assignment<Lecture, Placement> assignment) { 110 super(assignment); 111 } 112 113 public void setIteration(long iteration) { 114 iIteration = iteration; 115 } 116 117 public long getIteration() { 118 return iIteration; 119 } 120 } 121}