    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 * @version CourseTT 1.3 (University Course Timetabling)<br>
    027 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    028 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    029 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    030 * <br>
    031 *          This library is free software; you can redistribute it and/or modify
    032 *          it under the terms of the GNU Lesser General Public License as
    033 *          published by the Free Software Foundation; either version 3 of the
    034 *          License, or (at your option) any later version. <br>
    035 * <br>
    036 *          This library is distributed in the hope that it will be useful, but
    037 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    038 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    039 *          Lesser General Public License for more details. <br>
    040 * <br>
    041 *          You should have received a copy of the GNU Lesser General Public
    042 *          License along with this library; if not see
    043 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    044 */
    045public class InstructorStudentHardConflict extends InstructorStudentConflict {
    046
    047    @Override
    048    public boolean isApplicable(Lecture l1, Lecture l2) {
    049        return super.isApplicable(l1, l2) && oneInstructorOtherHard(l1, l2);
    050    }
    051
    052    /**
    053     * One of the lectures is hard, there is a joint enrollment constraint between them, and
    054     * there is at least one student that is instructor for one lecture and the other lecture
    055     * is singleton.
    056     * @param l1 first placement
    057     * @param l2 second placement
    058     * @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
    059     */
    060    public static boolean oneInstructorOtherHard(Lecture l1, Lecture l2) {
    061        if (!hard(l1, l2)) return false;
    062        JenrlConstraint jenrl = l1.jenrlConstraint(l2);
    063        if (jenrl == null) return false;
    064        for (Student student: jenrl.getInstructors()) {
    065            if ((l1.isSingleSection() || student.getInstructor().variables().contains(jenrl.second())) &&
    066                (l2.isSingleSection() || student.getInstructor().variables().contains(jenrl.first())))
    067                return true;
    068        }
    069        return false;
    070    }
    071
    072    @Override
    073    public double getWeightDefault(DataProperties config) {
    074        return config.getPropertyDouble("Comparator.InstructorHardStudentConflictWeight", 10.0 * config.getPropertyDouble("Comparator.HardStudentConflictWeight", 5.0));
    075    }
    076
    077    @Override
    078    public String getPlacementSelectionWeightName() {
    079        return "Placement.NrInstructorHardStudConfsWeight";
    080    }
    081
    082    @Override
    083    public void getInfo(Assignment<Lecture, Placement> assignment, Map<String, String> info) {
    084    }
    085
    086    @Override
    087    public void getInfo(Assignment<Lecture, Placement> assignment, Map<String, String> info, Collection<Lecture> variables) {
    088    }
    089
    090}