001package org.cpsolver.exam.criteria;
002
003import java.util.Collection;
004import java.util.HashSet;
005import java.util.Map;
006import java.util.Set;
007
008import org.cpsolver.exam.model.Exam;
009import org.cpsolver.exam.model.ExamModel;
010import org.cpsolver.exam.model.ExamPeriod;
011import org.cpsolver.exam.model.ExamPlacement;
012import org.cpsolver.exam.model.ExamStudent;
013import org.cpsolver.ifs.assignment.Assignment;
014import org.cpsolver.ifs.util.DataProperties;
015
016
017/**
018 * Number of more than two exams a day student conflicts. I.e., when an
019 * exam is attended by a student student that attends two or more other
020 * exams at the same day.
021 * <br><br>
022 * More than two exams a day student conflict weight can be set by
023 * problem property Exams.MoreThanTwoADayWeight, or in the input
024 * xml file, property moreThanTwoADayWeight.
025 * 
026 * <br>
027 * 
028 * @version ExamTT 1.3 (Examination Timetabling)<br>
029 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
030 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
031 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
032 * <br>
033 *          This library is free software; you can redistribute it and/or modify
034 *          it under the terms of the GNU Lesser General Public License as
035 *          published by the Free Software Foundation; either version 3 of the
036 *          License, or (at your option) any later version. <br>
037 * <br>
038 *          This library is distributed in the hope that it will be useful, but
039 *          WITHOUT ANY WARRANTY; without even the implied warranty of
040 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
041 *          Lesser General Public License for more details. <br>
042 * <br>
043 *          You should have received a copy of the GNU Lesser General Public
044 *          License along with this library; if not see
045 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
046 */
047public class StudentMoreThan2ADayConflicts extends ExamCriterion {
048
049    @Override
050    public String getWeightName() {
051        return "Exams.MoreThanTwoADayWeight";
052    }
053    
054    @Override
055    public double getWeightDefault(DataProperties config) {
056        return 100.0;
057    }
058
059    @Override
060    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
061        Exam exam = value.variable();
062        int penalty = 0;
063        ExamPeriod period = value.getPeriod();
064        Map<ExamStudent, Set<Exam>> students = ((ExamModel)getModel()).getStudentsOfDay(assignment, period);
065        for (ExamStudent s : exam.getStudents()) {
066            Set<Exam> exams = students.get(s);
067            if (exams == null || exams.size() < 2) continue;
068            int nrExams = exams.size() + (exams.contains(exam) ? 0 : 1);
069            if (nrExams > 2)
070                penalty++;
071        }
072        /*
073        for (ExamStudent s : exam.getStudents()) {
074            Set<Exam> exams = s.getExamsADay(assignment, period);
075            int nrExams = exams.size() + (exams.contains(exam) ? 0 : 1);
076            if (nrExams > 2)
077                penalty++;
078        }
079        */
080        return penalty;
081    }
082    
083    @Override
084    public String getName() {
085        return "More Than 2 A Day Conflicts";
086    }
087    
088    @Override
089    public String getXmlWeightName() {
090        return "moreThanTwoADayWeight";
091    }
092
093    @Override
094    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
095        if (getValue(assignment) != 0.0)
096            info.put(getName(), sDoubleFormat.format(getValue(assignment)));
097    }
098    
099    @Override
100    public double getValue(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
101        int ret = 0;
102        ExamModel m = (ExamModel)getModel();
103        Set<Integer> days = new HashSet<Integer>();
104        for (ExamPeriod p: m.getPeriods()) {
105            if (days.add(p.getDay())) {
106                Map<ExamStudent, Set<Exam>> students = ((ExamModel)getModel()).getStudentsOfDay(assignment, p);
107                for (Set<Exam> exams: students.values()) {
108                    int nrExams = exams.size();
109                    if (nrExams > 2)
110                        ret += nrExams - 2;
111                }
112            }
113        }
114        return ret;
115    }
116    
117    @Override
118    public String toString(Assignment<Exam, ExamPlacement> assignment) {
119        return "M2D:" + sDoubleFormat.format(getValue(assignment));
120    }
121}