    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.ExamPlacement;
    008import org.cpsolver.exam.model.ExamRoomPlacement;
    009import org.cpsolver.ifs.assignment.Assignment;
    010import org.cpsolver.ifs.util.DataProperties;
    011
    012
    013/**
    014 * Room split distance penalty. I.e., average distance between two rooms of a placement.
    015 * <br><br>
    016 * A weight for room split penalty can be set by problem
    017 * property Exams.RoomSplitWeight, or in the input xml file, property
    018 * roomSplitDistanceWeight).
    019 *
    020 * <br>
    021 *
    022 * @version ExamTT 1.3 (Examination Timetabling)<br>
    023 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
    024 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    025 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    026 * <br>
    027 *          This library is free software; you can redistribute it and/or modify
    028 *          it under the terms of the GNU Lesser General Public License as
    029 *          published by the Free Software Foundation; either version 3 of the
    030 *          License, or (at your option) any later version. <br>
    031 * <br>
    032 *          This library is distributed in the hope that it will be useful, but
    033 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    034 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    035 *          Lesser General Public License for more details. <br>
    036 * <br>
    037 *          You should have received a copy of the GNU Lesser General Public
    038 *          License along with this library; if not see
    039 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    040 */
    041public class RoomSplitDistancePenalty  extends ExamCriterion {
    042
    043    @Override
    044    public ValueContext createAssignmentContext(Assignment<Exam, ExamPlacement> assignment) {
    045        return new RoomSplitContext(assignment);
    046    }
    047
    048    @Override
    049    public String getWeightName() {
    050        return "Exams.RoomSplitDistanceWeight";
    051    }
    052
    053    @Override
    054    public String getXmlWeightName() {
    055        return "roomSplitDistanceWeight";
    056    }
    057
    058    @Override
    059    public double getWeightDefault(DataProperties config) {
    060        return 0.01;
    061    }
    062
    063    @Override
    064    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    065        if (value.getRoomPlacements() == null || value.getRoomPlacements().size() <= 1) return 0.0;
    066        double distance = 0.0;
    067        for (ExamRoomPlacement r : value.getRoomPlacements()) {
    068            for (ExamRoomPlacement w : value.getRoomPlacements()) {
    069                if (r.getRoom().getId() < w.getRoom().getId())
    070                    distance += r.getRoom().getDistanceInMeters(w.getRoom());
    071            }
    072        }
    073        int pairs = value.getRoomPlacements().size() * (value.getRoomPlacements().size() - 1) / 2;
    074        return distance / pairs;
    075    }
    076
    077    @Override
    078    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
    079        if (getValue(assignment) != 0.0) {
    080            info.put(getName(), sDoubleFormat.format(getValue(assignment) / nrRoomSplits(assignment)) + " m");
    081        }
    082    }
    083
    084    @Override
    085    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    086        return "RSd:" + sDoubleFormat.format(getValue(assignment) / nrRoomSplits(assignment));
    087    }
    088
    089    public int nrRoomSplits(Assignment<Exam, ExamPlacement> assignment) {
    090        return ((RoomSplitContext)getContext(assignment)).nrRoomSplits();
    091    }
    092
    093    @Override
    094    public boolean isPeriodCriterion() { return false; }
    095
    096    protected class RoomSplitContext extends ValueContext {
    097        private int iRoomSplits = 0;
    098
    099        public RoomSplitContext(Assignment<Exam, ExamPlacement> assignment) {
    100            super(assignment);
    101            for (Exam exam: getModel().variables()) {
    102                ExamPlacement placement = assignment.getValue(exam);
    103                if (placement != null && placement.getRoomPlacements() != null && placement.getRoomPlacements().size() > 1)
    104                    iRoomSplits ++;
    105            }
    106        }
    107
    108        @Override
    109        public void assigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
    110            super.assigned(assignment, value);
    111            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1)
    112                iRoomSplits ++;
    113        }
    114
    115        @Override
    116        public void unassigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
    117            super.unassigned(assignment, value);
    118            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1)
    119                iRoomSplits --;
    120        }
    121
    122        public int nrRoomSplits() {
    123            return iRoomSplits;
    124        }
    125    }
    126}