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 * @author  Tomáš Müller
023 * @version ExamTT 1.3 (Examination Timetabling)<br>
024 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
025 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
026 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
027 * <br>
028 *          This library is free software; you can redistribute it and/or modify
029 *          it under the terms of the GNU Lesser General Public License as
030 *          published by the Free Software Foundation; either version 3 of the
031 *          License, or (at your option) any later version. <br>
032 * <br>
033 *          This library is distributed in the hope that it will be useful, but
034 *          WITHOUT ANY WARRANTY; without even the implied warranty of
035 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
036 *          Lesser General Public License for more details. <br>
037 * <br>
038 *          You should have received a copy of the GNU Lesser General Public
039 *          License along with this library; if not see
040 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
041 */
042public class RoomSplitPenalty extends ExamCriterion {
043    
044    @Override
045    public ValueContext createAssignmentContext(Assignment<Exam, ExamPlacement> assignment) {
046        return new RoomSplitContext(assignment);
047    }
048    
049    @Override
050    public String getWeightName() {
051        return "Exams.RoomSplitWeight";
052    }
053    
054    @Override
055    public String getXmlWeightName() {
056        return "roomSplitWeight";
057    }
058    
059    @Override
060    public double getWeightDefault(DataProperties config) {
061        return 10.0;
062    }
063
064    @Override
065    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
066        return (value.getRoomPlacements() == null || value.getRoomPlacements().size() <= 1 ? 0 : (value.getRoomPlacements().size() - 1) * (value.getRoomPlacements().size() - 1));
067    }
068
069    @Override
070    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
071        if (getValue(assignment) != 0.0) {
072            int[] roomSplits = ((RoomSplitContext)getContext(assignment)).getRoomSplits();
073            String split = "";
074            for (int i = 0; i < roomSplits.length; i++) {
075                if (roomSplits[i] > 0) {
076                    if (split.length() > 0)
077                        split += ", ";
078                    split += roomSplits[i] + "&times;" + (i + 2);
079                }
080            }
081            info.put(getName(), sDoubleFormat.format(getValue(assignment)) + " (" + split + ")");            
082        }
083    }
084
085    @Override
086    public String toString(Assignment<Exam, ExamPlacement> assignment) {
087        return "RSp:" + sDoubleFormat.format(getValue(assignment));
088    }
089
090    @Override
091    public boolean isPeriodCriterion() { return false; }
092    
093    protected class RoomSplitContext extends ValueContext {
094        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 };
095        
096        protected void ensureCapacity(int minCapacity) {
097            if (minCapacity > iRoomSplits.length){
098                int oldCapacity = iRoomSplits.length;
099                int newCapacity = oldCapacity + (oldCapacity / 2);
100                if (newCapacity < minCapacity)
101                    newCapacity = minCapacity + (minCapacity / 2);
102                iRoomSplits = Arrays.copyOf(iRoomSplits, newCapacity);
103            }
104        }
105
106        public RoomSplitContext(Assignment<Exam, ExamPlacement> assignment) {
107            super(assignment);
108            for (Exam exam: getModel().variables()) {
109                ExamPlacement placement = assignment.getValue(exam);
110                if (placement != null && placement.getRoomPlacements() != null && placement.getRoomPlacements().size() > 1) {
111                    ensureCapacity(placement.getRoomPlacements().size());
112                    iRoomSplits[placement.getRoomPlacements().size() - 2] ++;
113                }
114            }
115        }
116
117        @Override
118        public void assigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
119            super.assigned(assignment, value);
120            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1) {
121                ensureCapacity(value.getRoomPlacements().size());
122                iRoomSplits[value.getRoomPlacements().size() - 2] ++;
123            }
124        }
125
126        @Override
127        public void unassigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
128            super.unassigned(assignment, value);
129            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1) {
130                ensureCapacity(value.getRoomPlacements().size());
131                iRoomSplits[value.getRoomPlacements().size() - 2] --;
132            }
133        }
134        
135        public int[] getRoomSplits() {
136            return iRoomSplits;
137        }
138    }
139}