001    package net.sf.cpsolver.coursett.criteria.additional;
002    
003    import java.util.Collection;
004    import java.util.Map;
005    
006    import net.sf.cpsolver.coursett.criteria.StudentConflict;
007    import net.sf.cpsolver.coursett.model.Lecture;
008    import net.sf.cpsolver.coursett.model.Placement;
009    import net.sf.cpsolver.coursett.model.TimeLocation;
010    import net.sf.cpsolver.ifs.solver.Solver;
011    import 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 Tomas Muller<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    
045    public 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    }