    001package org.cpsolver.exam.criteria;
    002
    003import java.util.Collection;
    004import java.util.Map;
    005import java.util.Set;
    006
    007import org.cpsolver.exam.model.Exam;
    008import org.cpsolver.exam.model.ExamModel;
    009import org.cpsolver.exam.model.ExamPeriod;
    010import org.cpsolver.exam.model.ExamPlacement;
    011import org.cpsolver.exam.model.ExamStudent;
    012import org.cpsolver.ifs.assignment.Assignment;
    013import org.cpsolver.ifs.util.DataProperties;
    014
    015
    016/**
    017 * Number of direct student conflicts. I.e., number of cases when an
    018 * exam is attended by a student that attends some other exam at the
    019 * same period.
    020 * <br><br>
    021 * Direct student conflict weight can be set by problem property
    022 * Exams.DirectConflictWeight, or in the input xml file, property
    023 * directConflictWeight.
    024 *
    025 * <br>
    026 *
    027 * @version ExamTT 1.3 (Examination Timetabling)<br>
    028 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
    029 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    030 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    031 * <br>
    032 *          This library is free software; you can redistribute it and/or modify
    033 *          it under the terms of the GNU Lesser General Public License as
    034 *          published by the Free Software Foundation; either version 3 of the
    035 *          License, or (at your option) any later version. <br>
    036 * <br>
    037 *          This library is distributed in the hope that it will be useful, but
    038 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    039 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    040 *          Lesser General Public License for more details. <br>
    041 * <br>
    042 *          You should have received a copy of the GNU Lesser General Public
    043 *          License along with this library; if not see
    044 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    045 */
    046public class StudentDirectConflicts extends ExamCriterion {
    047
    048    @Override
    049    public String getWeightName() {
    050        return "Exams.DirectConflictWeight";
    051    }
    052
    053    @Override
    054    public String getXmlWeightName() {
    055        return "directConflictWeight";
    056    }
    057
    058    @Override
    059    public double getWeightDefault(DataProperties config) {
    060        return 1000.0;
    061    }
    062
    063    @Override
    064    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    065        Exam exam = value.variable();
    066        int penalty = 0;
    067        ExamPeriod period = value.getPeriod();
    068        ExamModel m = (ExamModel)getModel();
    069        Map<ExamStudent, Set<Exam>> students = m.getStudentsOfPeriod(assignment, period);
    070        for (ExamStudent s : exam.getStudents()) {
    071            Set<Exam> exams = students.get(s);
    072            if (exams == null) continue;
    073            int nrExams = exams.size() + (exams.contains(exam) ? 0 : 1);
    074            if (nrExams > 1)
    075                penalty++;
    076        }
    077        if (m.isCheckForPeriodOverlaps()) {
    078            for (ExamPeriod p: m.getPeriods()) {
    079                if (period.hasIntersection(p)) {
    080                    Map<ExamStudent, Set<Exam>> others = m.getStudentsOfPeriod(assignment, p);
    081                    s: for (ExamStudent s : exam.getStudents()) {
    082                        Set<Exam> exams = students.get(s);
    083                        if (exams == null || exams.size() + (exams.contains(exam) ? 0 : 1) <= 1) {
    084                            Set<Exam> other = others.get(s);
    085                            if (other != null && !other.isEmpty())
    086                                for (Exam x: other) {
    087                                    if (period.hasIntersection(exam, x, p)) {
    088                                        penalty ++; continue s;
    089                                    }
    090                                }
    091                        }
    092                    }
    093                }
    094            }
    095        }
    096        /*
    097        for (ExamStudent s : exam.getStudents()) {
    098            Set<Exam> exams = s.getExams(assignment, period);
    099            if (exams.isEmpty()) continue;
    100            int nrExams = exams.size() + (exams.contains(exam) ? 0 : 1);
    101            if (nrExams > 1)
    102                penalty++;
    103        }
    104        */
    105        return penalty;
    106    }
    107
    108    @Override
    109    public String getName() {
    110        return "Direct Conflicts";
    111    }
    112
    113    @Override
    114    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
    115        StudentNotAvailableConflicts na = (StudentNotAvailableConflicts)getModel().getCriterion(StudentNotAvailableConflicts.class);
    116        if (getValue(assignment) != 0.0 || (na != null && na.getValue(assignment) != 0.0))
    117            info.put(getName(), sDoubleFormat.format(getValue(assignment) + (na == null ? 0.0 : na.getValue(assignment))) +
    118                    (na == null || na.getValue(assignment) == 0.0 ? "" : " (" + sDoubleFormat.format(na.getValue(assignment)) + " N/A)"));
    119    }
    120
    121    @Override
    122    public double getValue(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
    123        int ret = 0;
    124        ExamModel m = (ExamModel)getModel();
    125        for (ExamPeriod p: m.getPeriods()) {
    126            Map<ExamStudent, Set<Exam>> students = ((ExamModel)getModel()).getStudentsOfPeriod(assignment, p);
    127            for (Set<Exam> exams: students.values()) {
    128                int nrExams = exams.size();
    129                if (nrExams > 1)
    130                    ret += nrExams - 1;
    131            }
    132        }
    133        if (m.isCheckForPeriodOverlaps()) {
    134            for (ExamPeriod p: m.getPeriods()) {
    135                for (ExamPeriod q: m.getPeriods()) {
    136                    if (p.getIndex() < q.getIndex() && p.hasIntersection(q)) {
    137                        Map<ExamStudent, Set<Exam>> s1 = m.getStudentsOfPeriod(assignment, p);
    138                        Map<ExamStudent, Set<Exam>> s2 = m.getStudentsOfPeriod(assignment, q);
    139                        for (Map.Entry<ExamStudent, Set<Exam>> e: s1.entrySet()) {
    140                            ExamStudent s = e.getKey();
    141                            if (!e.getValue().isEmpty()) {
    142                                Set<Exam> x = s2.get(s);
    143                                if (x != null && x.isEmpty()) {
    144                                    x1: for (Exam x1: e.getValue()) {
    145                                        for (Exam x2: x) {
    146                                            if (p.hasIntersection(x1, x2, q)) {
    147                                                ret += 1; break x1;
    148                                            }
    149                                        }
    150                                    }
    151                                }
    152                            }
    153                        }
    154                    }
    155                }
    156            }
    157        }
    158        return ret;
    159    }
    160
    161    @Override
    162    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    163        return "DC:" + sDoubleFormat.format(getValue(assignment));
    164    }
    165}