001package net.sf.cpsolver.exam.criteria;
002
003import java.util.Set;
004
005import net.sf.cpsolver.exam.model.Exam;
006import net.sf.cpsolver.exam.model.ExamPlacement;
007import net.sf.cpsolver.exam.model.ExamRoomPlacement;
008import net.sf.cpsolver.ifs.util.DataProperties;
009
010/**
011 * Room perturbation penalty. I.e., number of assigned rooms different from
012 * initial. Only applicable when {@link PerturbationPenalty#isMPP()} is true (minimal
013 * perturbation problem).
014 * <br><br>
015 * A weight of room perturbations (i.e., a penalty for
016 * an assignment of an exam to a room different from the initial one) can be
017 * set by problem property Exams.RoomPerturbationWeight, or in the input xml
018 * file, property roomPerturbationWeight).
019 * 
020 * <br>
021 * 
022 * @version ExamTT 1.2 (Examination Timetabling)<br>
023 *          Copyright (C) 2008 - 2012 Tomáš Müller<br>
024 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
025 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
026 * <br>
027 *          This library is free software; you can redistribute it and/or modify
028 *          it under the terms of the GNU Lesser General Public License as
029 *          published by the Free Software Foundation; either version 3 of the
030 *          License, or (at your option) any later version. <br>
031 * <br>
032 *          This library is distributed in the hope that it will be useful, but
033 *          WITHOUT ANY WARRANTY; without even the implied warranty of
034 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
035 *          Lesser General Public License for more details. <br>
036 * <br>
037 *          You should have received a copy of the GNU Lesser General Public
038 *          License along with this library; if not see
039 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
040 */
041public class RoomPerturbationPenalty extends PerturbationPenalty {
042    
043    @Override
044    public String getWeightName() {
045        return "Exams.RoomPerturbationWeight";
046    }
047    
048    @Override
049    public String getXmlWeightName() {
050        return "roomPerturbationWeight";
051    }
052    
053    @Override
054    public double getWeightDefault(DataProperties config) {
055        return 0.01;
056    }
057
058    @Override
059    public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
060        if (!isMPP()) return 0;
061        Exam exam = value.variable();
062        ExamPlacement initial = exam.getInitialAssignment();
063        if (initial == null) return 0;
064        int penalty = 0;
065        if (value.getRoomPlacements() != null)
066            for (ExamRoomPlacement rp : value.getRoomPlacements()) {
067                if (initial.getRoomPlacements() == null || !initial.getRoomPlacements().contains(rp))
068                    penalty++;
069            }
070        return penalty;
071    }
072
073
074    @Override
075    public String toString() {
076        return (isMPP() ? "IRP:" + sDoubleFormat.format(getValue()) : "");
077    }
078
079    @Override
080    public boolean isPeriodCriterion() { return false; }
081}