    001package org.cpsolver.coursett.criteria.additional;
    002
    003import java.util.Collection;
    004import java.util.Map;
    005
    006import org.cpsolver.coursett.constraint.JenrlConstraint;
    007import org.cpsolver.coursett.model.Lecture;
    008import org.cpsolver.coursett.model.Placement;
    009import org.cpsolver.coursett.model.Student;
    010import org.cpsolver.ifs.assignment.Assignment;
    011import org.cpsolver.ifs.util.DataProperties;
    012
    013
    014/**
    015 * Instructor student conflicts. This criterion penalizes cases when an instructor (of a class) is attending some
    016 * other class as a student and there is a conflict between the two classes. Also, there is no alternative for the
    017 * student class (the conflict cannot be sectioned away).
    018 * <br>
    019 * To enable instructor student conflicts, set solver parameter Global.LoadStudentInstructorConflicts to true. Also
    020 * student course requests should be used in this case (to be able to match an instructor external id to a student
    021 * external id).
    022 * <br>
    023 * Hard instructor student conflicts are weighted by Comparator.InstructorHardStudentConflictWeight.
    024 * <br>
    025 *
    026 * @author  Tomáš Müller
    027 * @version CourseTT 1.3 (University Course Timetabling)<br>
    028 *          Copyright (C) 2006 - 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 InstructorStudentHardConflict extends InstructorStudentConflict {
    047
    048    @Override
    049    public boolean isApplicable(Lecture l1, Lecture l2) {
    050        return super.isApplicable(l1, l2) && oneInstructorOtherHard(l1, l2);
    051    }
    052
    053    /**
    054     * One of the lectures is hard, there is a joint enrollment constraint between them, and
    055     * there is at least one student that is instructor for one lecture and the other lecture
    056     * is singleton.
    057     * @param l1 first placement
    058     * @param l2 second placement
    059     * @return true if there is at least one student of one class teaching the other class, and there are no possibility to move the student into an alternative class
    060     */
    061    public static boolean oneInstructorOtherHard(Lecture l1, Lecture l2) {
    062        if (!hard(l1, l2)) return false;
    063        JenrlConstraint jenrl = l1.jenrlConstraint(l2);
    064        if (jenrl == null) return false;
    065        for (Student student: jenrl.getInstructors()) {
    066            if ((l1.isSingleSection() || student.getInstructor().variables().contains(jenrl.second())) &&
    067                (l2.isSingleSection() || student.getInstructor().variables().contains(jenrl.first())))
    068                return true;
    069        }
    070        return false;
    071    }
    072
    073    @Override
    074    public double getWeightDefault(DataProperties config) {
    075        return config.getPropertyDouble("Comparator.InstructorHardStudentConflictWeight", 10.0 * config.getPropertyDouble("Comparator.HardStudentConflictWeight", 5.0));
    076    }
    077
    078    @Override
    079    public String getPlacementSelectionWeightName() {
    080        return "Placement.NrInstructorHardStudConfsWeight";
    081    }
    082
    083    @Override
    084    public void getInfo(Assignment<Lecture, Placement> assignment, Map<String, String> info) {
    085    }
    086
    087    @Override
    088    public void getInfo(Assignment<Lecture, Placement> assignment, Map<String, String> info, Collection<Lecture> variables) {
    089    }
    090
    091}