001 package net.sf.cpsolver.coursett.criteria.placement;
002
003 import java.util.Collection;
004 import java.util.Map;
005 import java.util.Set;
006
007 import net.sf.cpsolver.coursett.model.Lecture;
008 import net.sf.cpsolver.coursett.model.Placement;
009 import net.sf.cpsolver.ifs.extension.ConflictStatistics;
010 import net.sf.cpsolver.ifs.extension.Extension;
011 import net.sf.cpsolver.ifs.solution.Solution;
012 import net.sf.cpsolver.ifs.solution.SolutionListener;
013 import net.sf.cpsolver.ifs.solver.Solver;
014
015 /**
016 * Hard conflicts weighted by the conflict-based statistics (past occurrences).
017 * <br>
018 *
019 * @version CourseTT 1.2 (University Course Timetabling)<br>
020 * Copyright (C) 2006 - 2011 Tomas Muller<br>
021 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
022 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
023 * <br>
024 * This library is free software; you can redistribute it and/or modify
025 * it under the terms of the GNU Lesser General Public License as
026 * published by the Free Software Foundation; either version 3 of the
027 * License, or (at your option) any later version. <br>
028 * <br>
029 * This library is distributed in the hope that it will be useful, but
030 * WITHOUT ANY WARRANTY; without even the implied warranty of
031 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
032 * Lesser General Public License for more details. <br>
033 * <br>
034 * You should have received a copy of the GNU Lesser General Public
035 * License along with this library; if not see
036 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
037 */
038 public class WeightedHardConflicts extends PlacementSelectionCriterion implements SolutionListener<Lecture, Placement> {
039 protected ConflictStatistics<Lecture, Placement> iStat = null;
040 protected long iIteration = 0;
041
042 @Override
043 public boolean init(Solver<Lecture, Placement> solver) {
044 super.init(solver);
045 for (Extension<Lecture, Placement> extension : solver.getExtensions()) {
046 if (ConflictStatistics.class.isInstance(extension))
047 iStat = (ConflictStatistics<Lecture, Placement>) extension;
048 }
049 solver.currentSolution().addSolutionListener(this);
050 return true;
051 }
052
053 @Override
054 public String getPlacementSelectionWeightName() {
055 return "Placement.NrConflictsWeight";
056 }
057
058 @Override
059 public double getValue(Placement value, Set<Placement> conflicts) {
060 return (iStat == null || conflicts == null ? 0.0 : iStat.countRemovals(iIteration, conflicts, value));
061 }
062
063 @Override
064 public double getPlacementSelectionWeightDefault(int level) {
065 return (level == 0 ? 3.0 : 0.0);
066 }
067
068 @Override
069 public void solutionUpdated(Solution<Lecture, Placement> solution) {
070 iIteration = solution.getIteration();
071 }
072
073 @Override
074 public void getInfo(Solution<Lecture, Placement> solution, Map<String, String> info) {
075 }
076
077 @Override
078 public void getInfo(Solution<Lecture, Placement> solution, Map<String, String> info, Collection<Lecture> variables) {
079 }
080
081 @Override
082 public void bestCleared(Solution<Lecture, Placement> solution) {
083 iIteration = solution.getIteration();
084 }
085
086 @Override
087 public void bestSaved(Solution<Lecture, Placement> solution) {
088 iIteration = solution.getIteration();
089 }
090
091 @Override
092 public void bestRestored(Solution<Lecture, Placement> solution) {
093 iIteration = solution.getIteration();
094 }
095
096 }