001package org.cpsolver.exam.criteria;
002
003import java.util.Collection;
004import java.util.Set;
005
006import org.cpsolver.exam.criteria.additional.RoomViolation;
007import org.cpsolver.exam.model.Exam;
008import org.cpsolver.exam.model.ExamModel;
009import org.cpsolver.exam.model.ExamPeriod;
010import org.cpsolver.exam.model.ExamPlacement;
011import org.cpsolver.exam.model.ExamRoom;
012import org.cpsolver.exam.model.ExamRoomPlacement;
013import org.cpsolver.ifs.assignment.Assignment;
014import org.cpsolver.ifs.solver.Solver;
015import org.cpsolver.ifs.util.DataProperties;
016
017
018/**
019 * Room penalty (penalty for using given rooms). I.e., sum of
020 * {@link ExamRoomPlacement#getPenalty(ExamPeriod)} of assigned rooms.
021 * <br><br>
022 * A weight for room penalty can be set by problem property
023 * Exams.RoomPreferenceWeight, or in the input xml file, property
024 * roomWeight).
025 * 
026 * <br>
027 * 
028 * @author  Tomáš Müller
029 * @version ExamTT 1.3 (Examination Timetabling)<br>
030 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
031 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
032 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
033 * <br>
034 *          This library is free software; you can redistribute it and/or modify
035 *          it under the terms of the GNU Lesser General Public License as
036 *          published by the Free Software Foundation; either version 3 of the
037 *          License, or (at your option) any later version. <br>
038 * <br>
039 *          This library is distributed in the hope that it will be useful, but
040 *          WITHOUT ANY WARRANTY; without even the implied warranty of
041 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
042 *          Lesser General Public License for more details. <br>
043 * <br>
044 *          You should have received a copy of the GNU Lesser General Public
045 *          License along with this library; if not see
046 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
047 */
048public class RoomPenalty extends ExamCriterion {
049    protected Integer iSoftRooms = null;
050    
051    @Override
052    public boolean init(Solver<Exam, ExamPlacement> solver) {
053        if (super.init(solver)) {
054            iSoftRooms = solver.getProperties().getPropertyInteger("Exam.SoftRooms", null);
055            if (iSoftRooms != null) {
056                RoomViolation rv = new RoomViolation();
057                getModel().addCriterion(rv);
058                return rv.init(solver);
059            }
060        }
061        return true;
062    }
063    
064    @Override
065    public String getWeightName() {
066        return "Exams.RoomWeight";
067    }
068    
069    @Override
070    public String getXmlWeightName() {
071        return "roomWeight";
072    }
073    
074    @Override
075    public double getWeightDefault(DataProperties config) {
076        return 0.1;
077    }
078    
079    @Override
080    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
081        double penalty = 0.0;
082        if (value.getRoomPlacements() != null)
083            for (ExamRoomPlacement r : value.getRoomPlacements()) {
084                penalty += (iSoftRooms != null && (iSoftRooms == r.getPenalty() || iSoftRooms == r.getPenalty(value.getPeriod())) ? 0.0 : r.getPenalty(value.getPeriod()));
085            }
086        return penalty;
087    }
088    
089    private int getMinPenalty(ExamRoom r) {
090        int min = Integer.MAX_VALUE;
091        for (ExamPeriod p : ((ExamModel)getModel()).getPeriods()) {
092            if (r.isAvailable(p) && (iSoftRooms == null || r.getPenalty(p) != iSoftRooms)) {
093                min = Math.min(min, r.getPenalty(p));
094            }
095        }
096        return min;
097    }
098
099    private int getMaxPenalty(ExamRoom r) {
100        int max = Integer.MIN_VALUE;
101        for (ExamPeriod p : ((ExamModel)getModel()).getPeriods()) {
102            if (r.isAvailable(p) && (iSoftRooms == null || r.getPenalty(p) != iSoftRooms)) {
103                max = Math.max(max, r.getPenalty(p));
104            }
105        }
106        return max;
107    }
108    
109    private boolean isAvailable(ExamRoom r) {
110        for (ExamPeriod p : ((ExamModel)getModel()).getPeriods()) {
111            if (r.isAvailable(p) && (iSoftRooms == null || r.getPenalty(p) != iSoftRooms))
112                return true;
113        }
114        return false;
115    }
116
117    @Override
118    public double[] getBounds(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
119        double[] bounds = new double[] { 0.0, 0.0 };
120        for (Exam exam : variables) {
121            if (!exam.getRoomPlacements().isEmpty()) {
122                int minPenalty = Integer.MAX_VALUE, maxPenalty = Integer.MIN_VALUE;
123                for (ExamRoomPlacement roomPlacement : exam.getRoomPlacements()) {
124                    if (iSoftRooms != null && iSoftRooms == roomPlacement.getPenalty()) continue;
125                    if (!isAvailable(roomPlacement.getRoom())) continue;
126                    minPenalty = Math.min(minPenalty, 2 * roomPlacement.getPenalty() + getMinPenalty(roomPlacement.getRoom()));
127                    maxPenalty = Math.max(maxPenalty, 2 * roomPlacement.getPenalty() + getMaxPenalty(roomPlacement.getRoom()));
128                }
129                bounds[0] += minPenalty;
130                bounds[1] += maxPenalty;
131            }
132        }
133        return bounds;
134    }
135    
136    @Override
137    public String toString(Assignment<Exam, ExamPlacement> assignment) {
138        return "RP:" + sDoubleFormat.format(getValue(assignment));
139    }
140
141    @Override
142    public boolean isPeriodCriterion() { return false; }
143}