    001package org.cpsolver.exam.criteria;
    002
    003import java.util.Map;
    004import java.util.Set;
    005
    006import org.cpsolver.exam.model.Exam;
    007import org.cpsolver.exam.model.ExamInstructor;
    008import org.cpsolver.exam.model.ExamModel;
    009import org.cpsolver.exam.model.ExamPeriod;
    010import org.cpsolver.exam.model.ExamPlacement;
    011import org.cpsolver.ifs.assignment.Assignment;
    012import org.cpsolver.ifs.util.DataProperties;
    013
    014
    015/**
    016 * Number of back-to-back distance instructor conflicts. I.e., number of
    017 * cases when an exam is attended by an instructor that attends some other
    018 * exam at the previous {@link ExamPeriod#prev()} or following
    019 * {@link ExamPeriod#next()} period and the distance
    020 * {@link ExamPlacement#getDistanceInMeters(ExamPlacement)} between these two exams
    021 * is greater than {@link ExamModel#getBackToBackDistance()}. Distance
    022 * back-to-back conflicts are only considered between consecutive periods
    023 * that are of the same day.
    024 * <br><br>
    025 * Distance back-to-back instructor conflict weight can be set by problem
    026 * property Exams.InstructorDistanceBackToBackConflictWeight, or in the
    027 * input xml file, property instructorDistanceBackToBackConflictWeight.
    028 *
    029 * <br>
    030 *
    031 * @version ExamTT 1.3 (Examination Timetabling)<br>
    032 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
    033 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    034 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    035 * <br>
    036 *          This library is free software; you can redistribute it and/or modify
    037 *          it under the terms of the GNU Lesser General Public License as
    038 *          published by the Free Software Foundation; either version 3 of the
    039 *          License, or (at your option) any later version. <br>
    040 * <br>
    041 *          This library is distributed in the hope that it will be useful, but
    042 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    043 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    044 *          Lesser General Public License for more details. <br>
    045 * <br>
    046 *          You should have received a copy of the GNU Lesser General Public
    047 *          License along with this library; if not see
    048 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    049 */
    050public class InstructorDistanceBackToBackConflicts extends StudentDistanceBackToBackConflicts {
    051
    052    @Override
    053    public String getWeightName() {
    054        return "Exams.InstructorDistanceBackToBackConflictWeight";
    055    }
    056
    057    @Override
    058    public String getXmlWeightName() {
    059        return "instructorDistanceBackToBackConflictWeight";
    060    }
    061
    062    @Override
    063    public double getWeightDefault(DataProperties config) {
    064        return 25.0;
    065    }
    066
    067    @Override
    068    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    069        Exam exam = value.variable();
    070        double btbDist = getBackToBackDistance();
    071        if (btbDist < 0)
    072            return 0;
    073        int penalty = 0;
    074        ExamPeriod period = value.getPeriod();
    075        Map<ExamInstructor, Set<Exam>> prev = (period.prev() != null && period.prev().getDay() == period.getDay() ? ((ExamModel)getModel()).getInstructorsOfPeriod(assignment, period.prev()) : null);
    076        Map<ExamInstructor, Set<Exam>> next = (period.next() != null && period.next().getDay() == period.getDay() ? ((ExamModel)getModel()).getInstructorsOfPeriod(assignment, period.next()) : null);
    077        for (ExamInstructor s : exam.getInstructors()) {
    078            if (prev != null) {
    079                Set<Exam> exams = prev.get(s);
    080                if (exams != null)
    081                    for (Exam x : exams) {
    082                        if (x.equals(exam))
    083                            continue;
    084                        if (value.getDistanceInMeters(assignment.getValue(x)) > getBackToBackDistance())
    085                            penalty++;
    086                    }
    087            }
    088            if (next != null) {
    089                Set<Exam> exams = next.get(s);
    090                if (exams != null)
    091                    for (Exam x : exams) {
    092                        if (x.equals(exam))
    093                            continue;
    094                        if (value.getDistanceInMeters(assignment.getValue(x)) > getBackToBackDistance())
    095                            penalty++;
    096                    }
    097            }
    098        }
    099        /*
    100        for (ExamInstructor s : exam.getInstructors()) {
    101            if (period.prev() != null) {
    102                if (period.prev().getDay() == period.getDay()) {
    103                    for (Exam x : s.getExams(assignment, period.prev())) {
    104                        if (x.equals(exam))
    105                            continue;
    106                        if (value.getDistanceInMeters(assignment.getValue(x)) > btbDist)
    107                            penalty++;
    108                    }
    109                }
    110            }
    111            if (period.next() != null) {
    112                if (period.next().getDay() == period.getDay()) {
    113                    for (Exam x : s.getExams(assignment, period.next())) {
    114                        if (x.equals(exam))
    115                            continue;
    116                        if (value.getDistanceInMeters(assignment.getValue(x)) > btbDist)
    117                            penalty++;
    118                    }
    119                }
    120            }
    121        }
    122        */
    123        return penalty;
    124    }
    125
    126    @Override
    127    public String getName() {
    128        return "Instructor Distance Back-To-Back Conflicts";
    129    }
    130
    131    @Override
    132    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    133        return (getValue(assignment) <= 0.0 ? "" : "iBTBd:" + sDoubleFormat.format(getValue(assignment)));
    134    }
    135
    136    @Override
    137    public boolean isPeriodCriterion() { return false; }
    138}