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