    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 * @author  Tomáš Müller
    024 * @version ExamTT 1.3 (Examination Timetabling)<br>
    025 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
    026 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    027 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    028 * <br>
    029 *          This library is free software; you can redistribute it and/or modify
    030 *          it under the terms of the GNU Lesser General Public License as
    031 *          published by the Free Software Foundation; either version 3 of the
    032 *          License, or (at your option) any later version. <br>
    033 * <br>
    034 *          This library is distributed in the hope that it will be useful, but
    035 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    036 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    037 *          Lesser General Public License for more details. <br>
    038 * <br>
    039 *          You should have received a copy of the GNU Lesser General Public
    040 *          License along with this library; if not see
    041 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    042 */
    043public class DistributionViolation extends ExamCriterion {
    044
    045    public DistributionViolation() {
    046        super();
    047        setValueUpdateType(ValueUpdateType.NoUpdate);
    048    }
    049
    050    @Override
    051    public String getWeightName() {
    052        return "Exam.SoftDistributions";
    053    }
    054
    055    @Override
    056    public String getXmlWeightName() {
    057        return "softDistributions";
    058    }
    059
    060    @Override
    061    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    062        int penalty = 0;
    063        ExamPlacement original = assignment.getValue(value.variable());
    064        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
    065            if (dc.isHard() || getWeight() != dc.getWeight())
    066                continue;
    067            penalty += dc.countViolations(assignment, value);
    068            if (original != null) penalty -= dc.countViolations(assignment, original);
    069        }
    070        return penalty;
    071    }
    072
    073    @Override
    074    protected double[] computeBounds(Assignment<Exam, ExamPlacement> assignment) {
    075        double[] bounds = new double[] { 0.0, 0.0 };
    076        for (ExamDistributionConstraint dc : ((ExamModel)getModel()).getDistributionConstraints()) {
    077            if (!dc.isHard() && getWeight() == dc.getWeight())
    078                bounds[1] += dc.variables().size() * (dc.variables().size() - 1) / 2;
    079        }
    080        return bounds;
    081    }
    082
    083    @Override
    084    public boolean isRoomCriterion() { return true; }
    085
    086    @Override
    087    public double getRoomValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
    088        int penalty = 0;
    089        ExamPlacement original = assignment.getValue(value.variable());
    090        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
    091            if (dc.isHard() || getWeight() != dc.getWeight() || !dc.isRoomRelated())
    092                continue;
    093            penalty += dc.countViolations(assignment, value);
    094            if (original != null) penalty -= dc.countViolations(assignment, original);
    095        }
    096        return penalty;
    097    }
    098
    099    @Override
    100    public boolean isPeriodCriterion() { return true; }
    101
    102    @Override
    103    public double getPeriodValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
    104        int penalty = 0;
    105        ExamPlacement original = assignment.getValue(value.variable());
    106        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
    107            if (dc.isHard() || getWeight() != dc.getWeight() || !dc.isPeriodRelated())
    108                continue;
    109            penalty += dc.countViolations(assignment, value);
    110            if (original != null) penalty -= dc.countViolations(assignment, original);
    111        }
    112        return penalty;
    113    }
    114
    115    @Override
    116    public double getValue(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
    117        int penalty = 0;
    118        Set<ExamDistributionConstraint> added = new HashSet<ExamDistributionConstraint>();
    119        for (Exam exam: variables) {
    120            for (ExamDistributionConstraint dc : exam.getDistributionConstraints()) {
    121                if (added.add(dc)) {
    122                    if (dc.isHard() || getWeight() != dc.getWeight())
    123                        continue;
    124                    penalty += dc.countViolations(assignment);
    125                }
    126            }
    127        }
    128        return penalty;
    129    }
    130
    131    @Override
    132    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    133        return (getValue(assignment) <= 0.0 ? "" : "!D:" + sDoubleFormat.format(getValue(assignment)));
    134    }
    135}