001 package net.sf.cpsolver.exam.model;
002
003 import java.util.HashMap;
004 import java.util.HashSet;
005 import java.util.Map;
006 import java.util.Set;
007
008 import org.dom4j.Element;
009
010 import net.sf.cpsolver.coursett.IdConvertor;
011 import net.sf.cpsolver.ifs.model.Model;
012 import net.sf.cpsolver.ifs.util.DataProperties;
013
014 /**
015 * Room sharing model based on a pre-defined list of examination pairs. The relation needs to be populated
016 * using {@link PredefinedExamRoomSharing#addPair(Exam, Exam)} and it is persisted with the solution XML (see
017 * {@link ExamModel#save()}, canShareRoom element for each exam containing a comma separated list of exam ids).
018 * <br>
019 *
020 * @version ExamTT 1.2 (Examination Timetabling)<br>
021 * Copyright (C) 2008 - 2012 Tomas Muller<br>
022 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
023 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
024 * <br>
025 * This library is free software; you can redistribute it and/or modify
026 * it under the terms of the GNU Lesser General Public License as
027 * published by the Free Software Foundation; either version 3 of the
028 * License, or (at your option) any later version. <br>
029 * <br>
030 * This library is distributed in the hope that it will be useful, but
031 * WITHOUT ANY WARRANTY; without even the implied warranty of
032 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
033 * Lesser General Public License for more details. <br>
034 * <br>
035 * You should have received a copy of the GNU Lesser General Public
036 * License along with this library; if not see
037 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
038 */
039 public class PredefinedExamRoomSharing extends ExamRoomSharing {
040 private Map<Long, Set<Long>> iSharingMatrix = new HashMap<Long, Set<Long>>();
041
042 public PredefinedExamRoomSharing(Model<Exam, ExamPlacement> model, DataProperties config) {
043 super(model, config);
044 }
045
046 @Override
047 public boolean canShareRoom(Exam x1, Exam x2) {
048 if (x1.getId() < x2.getId()) {
049 Set<Long> exams = iSharingMatrix.get(x1.getId());
050 return exams != null && exams.contains(x2.getId());
051 } else {
052 Set<Long> exams = iSharingMatrix.get(x2.getId());
053 return exams != null && exams.contains(x1.getId());
054 }
055 }
056
057 /** Add a pair of exams that are allowed to share a room */
058 public void addPair(Exam x1, Exam x2) {
059 addPair(x1.getId(), x2.getId());
060 }
061
062 /** Add a pair of exams that are allowed to share a room */
063 public void addPair(Long examId1, Long examId2) {
064 if (examId1 < examId2) {
065 Set<Long> exams = iSharingMatrix.get(examId1);
066 if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId1, exams); }
067 exams.add(examId2);
068 } else {
069 Set<Long> exams = iSharingMatrix.get(examId2);
070 if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId2, exams); }
071 exams.add(examId1);
072 }
073 }
074
075 /** Clear examination pairs */
076 public void clear() {
077 iSharingMatrix.clear();
078 }
079
080 @Override
081 public void save(Exam exam, Element element, IdConvertor idConvertor) {
082 Set<Long> exams = iSharingMatrix.get(exam.getId());
083 if (exams != null) {
084 String ids = "";
085 for (Long id: exams) {
086 if (!ids.isEmpty()) ids += ",";
087 ids += (idConvertor == null ? id.toString() : idConvertor.convert("exam", id.toString()));
088 }
089 element.addElement("canShareRoom").setText(ids);
090 }
091 }
092
093 @Override
094 public void load(Exam exam, Element element) {
095 Element canShareRoom = element.element("canShareRoom");
096 if (canShareRoom == null) return;
097 for (String id: canShareRoom.getTextTrim().split(","))
098 addPair(exam.getId(), Long.valueOf(id.trim()));
099 }
100 }