001package net.sf.cpsolver.exam.criteria;
002
003import java.util.Map;
004import java.util.Set;
005
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 split distance penalty. I.e., average distance between two rooms of a placement.
012 * <br><br>
013 * A weight for room split penalty can be set by problem
014 * property Exams.RoomSplitWeight, or in the input xml file, property
015 * roomSplitDistanceWeight).
016 * 
017 * <br>
018 * 
019 * @version ExamTT 1.2 (Examination Timetabling)<br>
020 *          Copyright (C) 2008 - 2012 Tomáš Müller<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 */
038public class RoomSplitDistancePenalty  extends ExamCriterion {
039    private int iRoomSplits = 0;
040
041    @Override
042    public String getWeightName() {
043        return "Exams.RoomSplitDistanceWeight";
044    }
045    
046    @Override
047    public String getXmlWeightName() {
048        return "roomSplitDistanceWeight";
049    }
050    
051    @Override
052    public double getWeightDefault(DataProperties config) {
053        return 0.01;
054    }
055    
056    @Override
057    public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
058        if (value.getRoomPlacements() == null || value.getRoomPlacements().size() <= 1) return 0.0;
059        double distance = 0.0;
060        for (ExamRoomPlacement r : value.getRoomPlacements()) {
061            for (ExamRoomPlacement w : value.getRoomPlacements()) {
062                if (r.getRoom().getId() < w.getRoom().getId())
063                    distance += r.getRoom().getDistanceInMeters(w.getRoom());
064            }
065        }
066        int pairs = value.getRoomPlacements().size() * (value.getRoomPlacements().size() - 1) / 2;
067        return distance / pairs;
068    }
069    
070    @Override
071    public void beforeUnassigned(long iteration, ExamPlacement value) {
072        super.beforeUnassigned(iteration, value);
073        if (value.getRoomPlacements() == null || value.getRoomPlacements().size() > 1)
074            iRoomSplits --;
075    }
076    
077    @Override
078    public void afterAssigned(long iteration, ExamPlacement value) {
079        super.afterAssigned(iteration, value);
080        if (value.getRoomPlacements() == null || value.getRoomPlacements().size() > 1)
081            iRoomSplits ++;
082    }
083    
084    @Override
085    public void getInfo(Map<String, String> info) {
086        if (getValue() != 0.0) {
087            info.put(getName(), sDoubleFormat.format(getValue() / iRoomSplits) + " m");
088        }
089    }
090    
091    public int nrRoomSplits() {
092        return iRoomSplits;
093    }
094
095    @Override
096    public String toString() {
097        return "RSd:" + sDoubleFormat.format(getValue() / iRoomSplits);
098    }
099
100    @Override
101    public boolean isPeriodCriterion() { return false; }
102}