001package org.cpsolver.exam.criteria;
002
003import java.util.Map;
004import java.util.Set;
005
006import org.cpsolver.exam.model.Exam;
007import org.cpsolver.exam.model.ExamPlacement;
008import org.cpsolver.ifs.assignment.Assignment;
009import org.cpsolver.ifs.util.DataProperties;
010
011
012/**
013 * Cost for using more than one room (nrSplits^2).
014 * <br><br>
015 * A weight for room split penalty can be set by problem
016 * property Exams.RoomSplitWeight, or in the input xml file, property
017 * roomSplitWeight.
018 * 
019 * <br>
020 * 
021 * @version ExamTT 1.3 (Examination Timetabling)<br>
022 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
023 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
024 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
025 * <br>
026 *          This library is free software; you can redistribute it and/or modify
027 *          it under the terms of the GNU Lesser General Public License as
028 *          published by the Free Software Foundation; either version 3 of the
029 *          License, or (at your option) any later version. <br>
030 * <br>
031 *          This library is distributed in the hope that it will be useful, but
032 *          WITHOUT ANY WARRANTY; without even the implied warranty of
033 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
034 *          Lesser General Public License for more details. <br>
035 * <br>
036 *          You should have received a copy of the GNU Lesser General Public
037 *          License along with this library; if not see
038 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
039 */
040public class RoomSplitPenalty extends ExamCriterion {
041    
042    @Override
043    public ValueContext createAssignmentContext(Assignment<Exam, ExamPlacement> assignment) {
044        return new RoomSplitContext(assignment);
045    }
046    
047    @Override
048    public String getWeightName() {
049        return "Exams.RoomSplitWeight";
050    }
051    
052    @Override
053    public String getXmlWeightName() {
054        return "roomSplitWeight";
055    }
056    
057    @Override
058    public double getWeightDefault(DataProperties config) {
059        return 10.0;
060    }
061
062    @Override
063    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
064        return (value.getRoomPlacements() == null || value.getRoomPlacements().size() <= 1 ? 0 : (value.getRoomPlacements().size() - 1) * (value.getRoomPlacements().size() - 1));
065    }
066
067    @Override
068    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
069        if (getValue(assignment) != 0.0) {
070            int[] roomSplits = ((RoomSplitContext)getContext(assignment)).getRoomSplits();
071            String split = "";
072            for (int i = 0; i < roomSplits.length; i++) {
073                if (roomSplits[i] > 0) {
074                    if (split.length() > 0)
075                        split += ", ";
076                    split += roomSplits[i] + "&times;" + (i + 2);
077                }
078            }
079            info.put(getName(), sDoubleFormat.format(getValue(assignment)) + " (" + split + ")");            
080        }
081    }
082
083    @Override
084    public String toString(Assignment<Exam, ExamPlacement> assignment) {
085        return "RSp:" + sDoubleFormat.format(getValue(assignment));
086    }
087
088    @Override
089    public boolean isPeriodCriterion() { return false; }
090    
091    protected class RoomSplitContext extends ValueContext {
092        private int iRoomSplits[] = new int[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
093
094        public RoomSplitContext(Assignment<Exam, ExamPlacement> assignment) {
095            super(assignment);
096            for (Exam exam: getModel().variables()) {
097                ExamPlacement placement = assignment.getValue(exam);
098                if (placement != null && placement.getRoomPlacements() != null && placement.getRoomPlacements().size() > 1)
099                    iRoomSplits[placement.getRoomPlacements().size() - 2] ++;
100            }
101        }
102
103        @Override
104        public void assigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
105            super.assigned(assignment, value);
106            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1)
107                iRoomSplits[value.getRoomPlacements().size() - 2] ++;
108        }
109
110        @Override
111        public void unassigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
112            super.unassigned(assignment, value);
113            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1)
114                iRoomSplits[value.getRoomPlacements().size() - 2] --;
115        }
116        
117        public int[] getRoomSplits() {
118            return iRoomSplits;
119        }
120    }
121}