    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 * @author  Tomáš Müller
    023 * @version ExamTT 1.3 (Examination Timetabling)<br>
    024 *          Copyright (C) 2008 - 2014 Tomáš Müller<br>
    025 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    026 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    027 * <br>
    028 *          This library is free software; you can redistribute it and/or modify
    029 *          it under the terms of the GNU Lesser General Public License as
    030 *          published by the Free Software Foundation; either version 3 of the
    031 *          License, or (at your option) any later version. <br>
    032 * <br>
    033 *          This library is distributed in the hope that it will be useful, but
    034 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    035 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    036 *          Lesser General Public License for more details. <br>
    037 * <br>
    038 *          You should have received a copy of the GNU Lesser General Public
    039 *          License along with this library; if not see
    040 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    041 */
    042public class RoomSplitDistancePenalty  extends ExamCriterion {
    043
    044    @Override
    045    public ValueContext createAssignmentContext(Assignment<Exam, ExamPlacement> assignment) {
    046        return new RoomSplitContext(assignment);
    047    }
    048
    049    @Override
    050    public String getWeightName() {
    051        return "Exams.RoomSplitDistanceWeight";
    052    }
    053
    054    @Override
    055    public String getXmlWeightName() {
    056        return "roomSplitDistanceWeight";
    057    }
    058
    059    @Override
    060    public double getWeightDefault(DataProperties config) {
    061        return 0.01;
    062    }
    063
    064    @Override
    065    public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) {
    066        if (value.getRoomPlacements() == null || value.getRoomPlacements().size() <= 1) return 0.0;
    067        double distance = 0.0;
    068        for (ExamRoomPlacement r : value.getRoomPlacements()) {
    069            for (ExamRoomPlacement w : value.getRoomPlacements()) {
    070                if (r.getRoom().getId() < w.getRoom().getId())
    071                    distance += r.getRoom().getDistanceInMeters(w.getRoom());
    072            }
    073        }
    074        int pairs = value.getRoomPlacements().size() * (value.getRoomPlacements().size() - 1) / 2;
    075        return distance / pairs;
    076    }
    077
    078    @Override
    079    public void getInfo(Assignment<Exam, ExamPlacement> assignment, Map<String, String> info) {
    080        if (getValue(assignment) != 0.0) {
    081            info.put(getName(), sDoubleFormat.format(getValue(assignment) / nrRoomSplits(assignment)) + " m");
    082        }
    083    }
    084
    085    @Override
    086    public String toString(Assignment<Exam, ExamPlacement> assignment) {
    087        return "RSd:" + sDoubleFormat.format(getValue(assignment) / nrRoomSplits(assignment));
    088    }
    089
    090    public int nrRoomSplits(Assignment<Exam, ExamPlacement> assignment) {
    091        return ((RoomSplitContext)getContext(assignment)).nrRoomSplits();
    092    }
    093
    094    @Override
    095    public boolean isPeriodCriterion() { return false; }
    096
    097    protected class RoomSplitContext extends ValueContext {
    098        private int iRoomSplits = 0;
    099
    100        public RoomSplitContext(Assignment<Exam, ExamPlacement> assignment) {
    101            super(assignment);
    102            for (Exam exam: getModel().variables()) {
    103                ExamPlacement placement = assignment.getValue(exam);
    104                if (placement != null && placement.getRoomPlacements() != null && placement.getRoomPlacements().size() > 1)
    105                    iRoomSplits ++;
    106            }
    107        }
    108
    109        @Override
    110        public void assigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
    111            super.assigned(assignment, value);
    112            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1)
    113                iRoomSplits ++;
    114        }
    115
    116        @Override
    117        public void unassigned(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value) {
    118            super.unassigned(assignment, value);
    119            if (value.getRoomPlacements() != null && value.getRoomPlacements().size() > 1)
    120                iRoomSplits --;
    121        }
    122
    123        public int nrRoomSplits() {
    124            return iRoomSplits;
    125        }
    126    }
    127}