001    package net.sf.cpsolver.exam.criteria;
002    
003    import java.util.Map;
004    import java.util.Set;
005    
006    import net.sf.cpsolver.exam.model.ExamPlacement;
007    import net.sf.cpsolver.exam.model.ExamRoomPlacement;
008    import 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 Tomas Muller<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     */
038    public 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    }