    001package org.cpsolver.exam.model;
    002
    003import java.util.HashMap;
    004import java.util.HashSet;
    005import java.util.Map;
    006import java.util.Set;
    007
    008import org.cpsolver.coursett.IdConvertor;
    009import org.cpsolver.ifs.assignment.Assignment;
    010import org.cpsolver.ifs.model.Model;
    011import org.cpsolver.ifs.util.DataProperties;
    012import org.dom4j.Element;
    013
    014
    015/**
    016 * Room sharing model based on a pre-defined list of examination pairs. The relation needs to be populated
    017 * using {@link PredefinedExamRoomSharing#addPair(Exam, Exam)} and it is persisted with the solution XML (see
    018 * {@link ExamModel#save(Assignment)}, canShareRoom element for each exam containing a comma separated list of exam ids).
    019 * <br>
    020 *
    021 * @author  Tomáš Müller
    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 PredefinedExamRoomSharing extends ExamRoomSharing {
    042    private Map<Long, Set<Long>> iSharingMatrix = new HashMap<Long, Set<Long>>();
    043
    044    public PredefinedExamRoomSharing(Model<Exam, ExamPlacement> model, DataProperties config) {
    045        super(model, config);
    046    }
    047
    048    @Override
    049    public boolean canShareRoom(Exam x1, Exam x2) {
    050        if (x1.getId() < x2.getId()) {
    051            Set<Long> exams = iSharingMatrix.get(x1.getId());
    052            return exams != null && exams.contains(x2.getId());
    053        } else {
    054            Set<Long> exams = iSharingMatrix.get(x2.getId());
    055            return exams != null && exams.contains(x1.getId());
    056        }
    057    }
    058
    059    /** Add a pair of exams that are allowed to share a room
    060     * @param x1 first exam
    061     * @param x2 second exam
    062     **/
    063    public void addPair(Exam x1, Exam x2) {
    064        addPair(x1.getId(), x2.getId());
    065    }
    066
    067    /** Add a pair of exams that are allowed to share a room
    068     * @param examId1 first exam unique id
    069     * @param examId2 second exam unique id
    070     **/
    071    public void addPair(Long examId1, Long examId2) {
    072        if (examId1 < examId2) {
    073            Set<Long> exams = iSharingMatrix.get(examId1);
    074            if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId1, exams); }
    075            exams.add(examId2);
    076        } else {
    077            Set<Long> exams = iSharingMatrix.get(examId2);
    078            if (exams == null) { exams = new HashSet<Long>(); iSharingMatrix.put(examId2, exams); }
    079            exams.add(examId1);
    080        }
    081    }
    082
    083    /** Clear examination pairs */
    084    public void clear() {
    085        iSharingMatrix.clear();
    086    }
    087
    088    @Override
    089    public void save(Exam exam, Element element, IdConvertor idConvertor) {
    090        Set<Long> exams = iSharingMatrix.get(exam.getId());
    091        if (exams != null) {
    092            String ids = "";
    093            for (Long id: exams) {
    094                if (!ids.isEmpty()) ids += ",";
    095                ids += (idConvertor == null ? id.toString() : idConvertor.convert("exam", id.toString()));
    096            }
    097            element.addElement("canShareRoom").setText(ids);
    098        }
    099    }
    100
    101    @Override
    102    public void load(Exam exam, Element element) {
    103        Element canShareRoom = element.element("canShareRoom");
    104        if (canShareRoom == null) return;
    105        for (String id: canShareRoom.getTextTrim().split(","))
    106            addPair(exam.getId(), Long.valueOf(id.trim()));
    107    }
    108}