001package org.cpsolver.exam.criteria.additional;
002
003import java.util.Collection;
004import java.util.HashSet;
005import java.util.Set;
006
007import org.cpsolver.exam.criteria.ExamCriterion;
008import org.cpsolver.exam.model.Exam;
009import org.cpsolver.exam.model.ExamDistributionConstraint;
010import org.cpsolver.exam.model.ExamModel;
011import org.cpsolver.exam.model.ExamPlacement;
012import org.cpsolver.ifs.assignment.Assignment;
013
014
015/**
016 * Experimental criterion counting violations of hard distribution constraints.
017 * <br><br>
018 * To enable breaking of hard distribution constraints, set parameter Exam.SoftDistributions to
019 * a weight that should be inferred by a hard distribution constraint being broken.
020 * 
021 * <br>
022 * 
023 * @version ExamTT 1.3 (Examination Timetabling)<br>
024 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
025 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
026 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
027 * <br>
028 *          This library is free software; you can redistribute it and/or modify
029 *          it under the terms of the GNU Lesser General Public License as
030 *          published by the Free Software Foundation; either version 3 of the
031 *          License, or (at your option) any later version. <br>
032 * <br>
033 *          This library is distributed in the hope that it will be useful, but
034 *          WITHOUT ANY WARRANTY; without even the implied warranty of
035 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
036 *          Lesser General Public License for more details. <br>
037 * <br>
038 *          You should have received a copy of the GNU Lesser General Public
039 *          License along with this library; if not see
040 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
041 */
042public class DistributionViolation extends ExamCriterion {
043
044    @Override
045    public String getWeightName() {
046        return "Exam.SoftDistributions";
047    }
048    
049    @Override
050    public String getXmlWeightName() {
051        return "softDistributions";
052    }
053
054    @Override
055    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
056        int penalty = 0;
057        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
058            if (dc.isHard() || getWeight() != dc.getWeight())
059                continue;
060            boolean sat = dc.isSatisfied(assignment, value);
061            if (sat != dc.isSatisfied(assignment))
062                penalty += (sat ? -1.0 : 1.0);
063        }
064        return penalty;
065    }
066    
067    @Override
068    protected double[] computeBounds(Assignment<Exam, ExamPlacement> assignment) {
069        double[] bounds = new double[] { 0.0, 0.0 };
070        for (ExamDistributionConstraint dc : ((ExamModel)getModel()).getDistributionConstraints()) {
071            if (!dc.isHard() && getWeight() == dc.getWeight())
072                bounds[1] ++;
073        }
074        return bounds;
075    }
076    
077    @Override
078    public boolean isRoomCriterion() { return true; }
079    
080    @Override
081    public double getRoomValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
082        int penalty = 0;
083        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
084            if (dc.isHard() || getWeight() != dc.getWeight() || !dc.isRoomRelated())
085                continue;
086            boolean sat = dc.isSatisfied(assignment, value);
087            if (sat != dc.isSatisfied(assignment))
088                penalty += (sat ? -1.0 : 1.0);
089        }
090        return penalty;
091    }
092
093    @Override
094    public boolean isPeriodCriterion() { return true; }
095    
096    @Override
097    public double getPeriodValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
098        int penalty = 0;
099        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
100            if (dc.isHard() || getWeight() != dc.getWeight() || !dc.isPeriodRelated())
101                continue;
102            boolean sat = dc.isSatisfied(assignment, value);
103            if (sat != dc.isSatisfied(assignment))
104                penalty += (sat ? -1.0 : 1.0);
105        }
106        return penalty;
107    }
108    
109    @Override
110    public double getValue(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
111        int penalty = 0;
112        Set<ExamDistributionConstraint> added = new HashSet<ExamDistributionConstraint>();
113        for (Exam exam: variables) {
114            for (ExamDistributionConstraint dc : exam.getDistributionConstraints()) {
115                if (added.add(dc)) {
116                    if (dc.isHard() || getWeight() != dc.getWeight())
117                        continue;
118                    if (!dc.isSatisfied(assignment))
119                        penalty += 1;
120                }
121            }
122        }
123        return penalty;
124    }
125
126    @Override
127    public String toString(Assignment<Exam, ExamPlacement> assignment) {
128        return (getValue(assignment) <= 0.0 ? "" : "!D:" + sDoubleFormat.format(getValue(assignment)));
129    }
130}