    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 * @author  Tomáš Müller
    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 StudentDirectConflicts extends ExamCriterion {
    048
    049    @Override
    050    public String getWeightName() {
    051        return "Exams.DirectConflictWeight";
    052    }
    053
    054    @Override
    055    public String getXmlWeightName() {
    056        return "directConflictWeight";
    057    }
    058
    059    @Override
    060    public double getWeightDefault(DataProperties config) {
    061        return 1000.0;
    062    }
    063
    064    @Override
    065    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    066        Exam exam = value.variable();
    067        int penalty = 0;
    068        ExamPeriod period = value.getPeriod();
    069        ExamModel m = (ExamModel)getModel();
    070        Map<ExamStudent, Set<Exam>> students = m.getStudentsOfPeriod(assignment, period);
    071        for (ExamStudent s : exam.getStudents()) {
    072            Set<Exam> exams = students.get(s);
    073            if (exams == null) continue;
    074            int nrExams = exams.size() + (exams.contains(exam) ? 0 : 1);
    075            if (nrExams > 1)
    076                penalty++;
    077        }
    078        if (m.isCheckForPeriodOverlaps()) {
    079            for (ExamPeriod p: m.getPeriods()) {
    080                if (period.hasIntersection(p)) {
    081                    Map<ExamStudent, Set<Exam>> others = m.getStudentsOfPeriod(assignment, p);
    082                    s: for (ExamStudent s : exam.getStudents()) {
    083                        Set<Exam> exams = students.get(s);
    084                        if (exams == null || exams.size() + (exams.contains(exam) ? 0 : 1) <= 1) {
    085                            Set<Exam> other = others.get(s);
    086                            if (other != null && !other.isEmpty())
    087                                for (Exam x: other) {
    088                                    if (period.hasIntersection(exam, x, p)) {
    089                                        penalty ++; continue s;
    090                                    }
    091                                }
    092                        }
    093                    }
    094                }
    095            }
    096        }
    097        /*
    098        for (ExamStudent s : exam.getStudents()) {
    099            Set<Exam> exams = s.getExams(assignment, period);
    100            if (exams.isEmpty()) continue;
    101            int nrExams = exams.size() + (exams.contains(exam) ? 0 : 1);
    102            if (nrExams > 1)
    103                penalty++;
    104        }
    105        */
    106        return penalty;
    107    }
    108
    109    @Override
    110    public String getName() {
    111        return "Direct Conflicts";
    112    }
    113
    114    @Override
    115    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
    116        StudentNotAvailableConflicts na = (StudentNotAvailableConflicts)getModel().getCriterion(StudentNotAvailableConflicts.class);
    117        if (getValue(assignment) != 0.0 || (na != null && na.getValue(assignment) != 0.0))
    118            info.put(getName(), sDoubleFormat.format(getValue(assignment) + (na == null ? 0.0 : na.getValue(assignment))) +
    119                    (na == null || na.getValue(assignment) == 0.0 ? "" : " (" + sDoubleFormat.format(na.getValue(assignment)) + " N/A)"));
    120    }
    121
    122    @Override
    123    public double getValue(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) {
    124        int ret = 0;
    125        ExamModel m = (ExamModel)getModel();
    126        for (ExamPeriod p: m.getPeriods()) {
    127            Map<ExamStudent, Set<Exam>> students = ((ExamModel)getModel()).getStudentsOfPeriod(assignment, p);
    128            for (Set<Exam> exams: students.values()) {
    129                int nrExams = exams.size();
    130                if (nrExams > 1)
    131                    ret += nrExams - 1;
    132            }
    133        }
    134        if (m.isCheckForPeriodOverlaps()) {
    135            for (ExamPeriod p: m.getPeriods()) {
    136                for (ExamPeriod q: m.getPeriods()) {
    137                    if (p.getIndex() < q.getIndex() && p.hasIntersection(q)) {
    138                        Map<ExamStudent, Set<Exam>> s1 = m.getStudentsOfPeriod(assignment, p);
    139                        Map<ExamStudent, Set<Exam>> s2 = m.getStudentsOfPeriod(assignment, q);
    140                        for (Map.Entry<ExamStudent, Set<Exam>> e: s1.entrySet()) {
    141                            ExamStudent s = e.getKey();
    142                            if (!e.getValue().isEmpty()) {
    143                                Set<Exam> x = s2.get(s);
    144                                if (x != null && x.isEmpty()) {
    145                                    x1: for (Exam x1: e.getValue()) {
    146                                        for (Exam x2: x) {
    147                                            if (p.hasIntersection(x1, x2, q)) {
    148                                                ret += 1; break x1;
    149                                            }
    150                                        }
    151                                    }
    152                                }
    153                            }
    154                        }
    155                    }
    156                }
    157            }
    158        }
    159        return ret;
    160    }
    161
    162    @Override
    163    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    164        return "DC:" + sDoubleFormat.format(getValue(assignment));
    165    }
    166}