001package org.cpsolver.exam.criteria;
002
003import java.util.Set;
004
005import org.cpsolver.exam.model.Exam;
006import org.cpsolver.exam.model.ExamPlacement;
007import org.cpsolver.exam.model.ExamRoomPlacement;
008import org.cpsolver.ifs.assignment.Assignment;
009import org.cpsolver.ifs.util.DataProperties;
010
011
012/**
013 * Room perturbation penalty. I.e., number of assigned rooms different from
014 * initial. Only applicable when {@link PerturbationPenalty#isMPP()} is true (minimal
015 * perturbation problem).
016 * <br><br>
017 * A weight of room perturbations (i.e., a penalty for
018 * an assignment of an exam to a room different from the initial one) can be
019 * set by problem property Exams.RoomPerturbationWeight, or in the input xml
020 * file, property roomPerturbationWeight).
021 * 
022 * <br>
023 * 
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 RoomPerturbationPenalty extends PerturbationPenalty {
044    
045    @Override
046    public String getWeightName() {
047        return "Exams.RoomPerturbationWeight";
048    }
049    
050    @Override
051    public String getXmlWeightName() {
052        return "roomPerturbationWeight";
053    }
054    
055    @Override
056    public double getWeightDefault(DataProperties config) {
057        return 0.01;
058    }
059
060    @Override
061    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
062        if (!isMPP()) return 0;
063        Exam exam = value.variable();
064        ExamPlacement initial = exam.getInitialAssignment();
065        if (initial == null) return 0;
066        int penalty = 0;
067        if (value.getRoomPlacements() != null)
068            for (ExamRoomPlacement rp : value.getRoomPlacements()) {
069                if (initial.getRoomPlacements() == null || !initial.getRoomPlacements().contains(rp))
070                    penalty++;
071            }
072        return penalty;
073    }
074
075
076    @Override
077    public String toString(Assignment<Exam, ExamPlacement> assignment) {
078        return (isMPP() ? "IRP:" + sDoubleFormat.format(getValue(assignment)) : "");
079    }
080
081    @Override
082    public boolean isPeriodCriterion() { return false; }
083}