001package org.cpsolver.exam.criteria;
002
003import java.util.Arrays;
004import java.util.Map;
005import java.util.Set;
006
007import org.cpsolver.exam.model.Exam;
008import org.cpsolver.exam.model.ExamPlacement;
009import org.cpsolver.ifs.assignment.Assignment;
010import org.cpsolver.ifs.util.DataProperties;
011
012
013/**
014 * Cost for using more than one room (nrSplits^2).
015 * <br><br>
016 * A weight for room split penalty can be set by problem
017 * property Exams.RoomSplitWeight, or in the input xml file, property
018 * roomSplitWeight.
019 * 
020 * <br>
021 * 
022 * @version ExamTT 1.3 (Examination Timetabling)<br>
023 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
024 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
025 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
026 * <br>
027 *          This library is free software; you can redistribute it and/or modify
028 *          it under the terms of the GNU Lesser General Public License as
029 *          published by the Free Software Foundation; either version 3 of the
030 *          License, or (at your option) any later version. <br>
031 * <br>
032 *          This library is distributed in the hope that it will be useful, but
033 *          WITHOUT ANY WARRANTY; without even the implied warranty of
034 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
035 *          Lesser General Public License for more details. <br>
036 * <br>
037 *          You should have received a copy of the GNU Lesser General Public
038 *          License along with this library; if not see
039 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
040 */
041public class RoomSplitPenalty extends ExamCriterion {
042    
043    @Override
044    public ValueContext createAssignmentContext(Assignment<Exam, ExamPlacement> assignment) {
045        return new RoomSplitContext(assignment);
046    }
047    
048    @Override
049    public String getWeightName() {
050        return "Exams.RoomSplitWeight";
051    }
052    
053    @Override
054    public String getXmlWeightName() {
055        return "roomSplitWeight";
056    }
057    
058    @Override
059    public double getWeightDefault(DataProperties config) {
060        return 10.0;
061    }
062
063    @Override
064    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
065        return (value.getRoomPlacements() == null || value.getRoomPlacements().size() <= 1 ? 0 : (value.getRoomPlacements().size() - 1) * (value.getRoomPlacements().size() - 1));
066    }
067
068    @Override
069    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
070        if (getValue(assignment) != 0.0) {
071            int[] roomSplits = ((RoomSplitContext)getContext(assignment)).getRoomSplits();
072            String split = "";
073            for (int i = 0; i < roomSplits.length; i++) {
074                if (roomSplits[i] > 0) {
075                    if (split.length() > 0)
076                        split += ", ";
077                    split += roomSplits[i] + "&times;" + (i + 2);
078                }
079            }
080            info.put(getName(), sDoubleFormat.format(getValue(assignment)) + " (" + split + ")");            
081        }
082    }
083
084    @Override
085    public String toString(Assignment<Exam, ExamPlacement> assignment) {
086        return "RSp:" + sDoubleFormat.format(getValue(assignment));
087    }
088
089    @Override
090    public boolean isPeriodCriterion() { return false; }
091    
092    protected class RoomSplitContext extends ValueContext {
093        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 };
094        
095        protected void ensureCapacity(int minCapacity) {
096            if (minCapacity > iRoomSplits.length){
097                int oldCapacity = iRoomSplits.length;
098                int newCapacity = oldCapacity + (oldCapacity / 2);
099                if (newCapacity < minCapacity)
100                    newCapacity = minCapacity + (minCapacity / 2);
101                iRoomSplits = Arrays.copyOf(iRoomSplits, newCapacity);
102            }
103        }
104
105        public RoomSplitContext(Assignment<Exam, ExamPlacement> assignment) {
106            super(assignment);
107            for (Exam exam: getModel().variables()) {
108                ExamPlacement placement = assignment.getValue(exam);
109                if (placement != null && placement.getRoomPlacements() != null && placement.getRoomPlacements().size() > 1) {
110                    ensureCapacity(placement.getRoomPlacements().size());
111                    iRoomSplits[placement.getRoomPlacements().size() - 2] ++;
112                }
113            }
114        }
115
116        @Override
117        public void assigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
118            super.assigned(assignment, value);
119            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1) {
120                ensureCapacity(value.getRoomPlacements().size());
121                iRoomSplits[value.getRoomPlacements().size() - 2] ++;
122            }
123        }
124
125        @Override
126        public void unassigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
127            super.unassigned(assignment, value);
128            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1) {
129                ensureCapacity(value.getRoomPlacements().size());
130                iRoomSplits[value.getRoomPlacements().size() - 2] --;
131            }
132        }
133        
134        public int[] getRoomSplits() {
135            return iRoomSplits;
136        }
137    }
138}