001package net.sf.cpsolver.coursett.criteria.additional;
002
003import java.util.Collection;
004import java.util.Map;
005
006import net.sf.cpsolver.coursett.criteria.StudentConflict;
007import net.sf.cpsolver.coursett.model.Lecture;
008import net.sf.cpsolver.coursett.model.Placement;
009import net.sf.cpsolver.coursett.model.TimeLocation;
010import net.sf.cpsolver.ifs.solver.Solver;
011import net.sf.cpsolver.ifs.util.DataProperties;
012
013/**
014 * Naive, yet effective approach for modeling student lunch breaks. This criterion
015 * is based on {@link StudentConflict} and it creates a conflict whenever there are
016 * two classes (that share students) overlapping with the lunch time which are one
017 * after the other with a break in between smaller than the requested lunch break.
018 * Lunch time is defined by StudentLunch.StartSlot and StudentLunch.EndStart
019 * properties (default is 11:00 am - 1:30 pm), with lunch break of at least
020 * StudentLunch.Length slots (default is 30 minutes). Such a conflict is weighted
021 * by Comparator.StudentLunchWeight, which defaults to Comparator.StudentConflictWeight.
022 * 
023 * <br>
024 * 
025 * @version CourseTT 1.2 (University Course Timetabling)<br>
026 *          Copyright (C) 2006 - 2011 Tomáš Müller<br>
027 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
028 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
029 * <br>
030 *          This library is free software; you can redistribute it and/or modify
031 *          it under the terms of the GNU Lesser General Public License as
032 *          published by the Free Software Foundation; either version 3 of the
033 *          License, or (at your option) any later version. <br>
034 * <br>
035 *          This library is distributed in the hope that it will be useful, but
036 *          WITHOUT ANY WARRANTY; without even the implied warranty of
037 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
038 *          Lesser General Public License for more details. <br>
039 * <br>
040 *          You should have received a copy of the GNU Lesser General Public
041 *          License along with this library; if not see
042 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
043 */
044
045public class StudentLuchBreak extends StudentConflict {
046    private int iLunchStart, iLunchEnd, iLunchLength; 
047    
048    @Override
049    public boolean init(Solver<Lecture, Placement> solver) {
050        iLunchStart = solver.getProperties().getPropertyInt("StudentLunch.StartSlot", (11 * 60) / 5);
051        iLunchEnd = solver.getProperties().getPropertyInt("StudentLunch.EndStart", (13 * 60 + 30) / 5);
052        iLunchLength = solver.getProperties().getPropertyInt("StudentLunch.Length", 30 / 5);
053        return super.init(solver);
054    }
055
056
057    @Override
058    public boolean isApplicable(Lecture l1, Lecture l2) {
059        return applicable(l1, l2);
060    }
061    
062    @Override
063    public double getWeightDefault(DataProperties config) {
064        return config.getPropertyDouble("Comparator.StudentLunchWeight", config.getPropertyDouble("Comparator.StudentConflictWeight", 1.0));
065    }
066    
067    @Override
068    public String getPlacementSelectionWeightName() {
069        return "Placement.StudentLunchWeight";
070    }
071
072    public boolean nolunch(Placement p1, Placement p2) {
073        if (p1 == null || p2 == null || overlaps(p1, p2)) return false;
074        if (p1.variable().isCommitted() && p2.variable().isCommitted()) return false;
075        TimeLocation t1 = p1.getTimeLocation(), t2 = p2.getTimeLocation();
076        if (!t1.shareDays(t2) || !t1.shareWeeks(t2)) return false;
077        int s1 = t1.getStartSlot(), s2 = t2.getStartSlot();
078        int e1 = t1.getStartSlot() + t1.getNrSlotsPerMeeting(), e2 = t2.getStartSlot() + t2.getNrSlotsPerMeeting();
079        if (e1 + iLunchLength > s2 && e2 + iLunchLength > s1 && e1 > iLunchStart && iLunchEnd > s1 && e2 > iLunchStart && iLunchEnd > s2)
080            return true;
081        return false;
082    }
083    
084    @Override
085    public boolean inConflict(Placement p1, Placement p2) {
086        return nolunch(p1, p2);
087    }
088    
089    @Override
090    public void getInfo(Map<String, String> info) {
091        super.getInfo(info);
092        double conf = getValue();
093        if (conf > 0.0)
094            info.put("Student lunch conflicts", String.valueOf(Math.round(conf)));
095    }
096    
097    @Override
098    public void getInfo(Map<String, String> info, Collection<Lecture> variables) {
099        super.getInfo(info, variables);
100        double conf = getValue(variables);
101        if (conf > 0.0)
102            info.put("Student lunch conflicts", String.valueOf(Math.round(conf)));
103    }
104
105}