    001package org.cpsolver.coursett.criteria.additional;
    002
    003import org.cpsolver.coursett.constraint.JenrlConstraint;
    004import org.cpsolver.coursett.criteria.StudentConflict;
    005import org.cpsolver.coursett.model.Lecture;
    006import org.cpsolver.coursett.model.Placement;
    007import org.cpsolver.coursett.model.Student;
    008import org.cpsolver.ifs.assignment.Assignment;
    009import org.cpsolver.ifs.util.DataProperties;
    010
    011/**
    012 * Quadratic student conflicts. Same as {@link StudentConflict}, however,
    013 * student joint enrollments are squared (1 conflict counts as 1, 2 as 4, 3 as 9, etc.).
    014 *
    015 * <br>
    016 *
    017 * @author  Tomáš Müller
    018 * @version CourseTT 1.3 (University Course Timetabling)<br>
    019 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    020 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    021 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    022 * <br>
    023 *          This library is free software; you can redistribute it and/or modify
    024 *          it under the terms of the GNU Lesser General Public License as
    025 *          published by the Free Software Foundation; either version 3 of the
    026 *          License, or (at your option) any later version. <br>
    027 * <br>
    028 *          This library is distributed in the hope that it will be useful, but
    029 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    030 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    031 *          Lesser General Public License for more details. <br>
    032 * <br>
    033 *          You should have received a copy of the GNU Lesser General Public
    034 *          License along with this library; if not see
    035 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    036 */
    037
    038public class QuadraticStudentConflict extends StudentConflict {
    039
    040    @Override
    041    public boolean isApplicable(Lecture l1, Lecture l2) {
    042        return l1 != null && l2 != null && !ignore(l1, l2) && applicable(l1, l2);
    043    }
    044
    045    @Override
    046    public double getWeightDefault(DataProperties config) {
    047        return config.getPropertyDouble("Comparator.StudentConflictWeight", 1.0);
    048    }
    049
    050    @Override
    051    public String getPlacementSelectionWeightName() {
    052        return "Placement.NrStudConfsWeight";
    053    }
    054
    055    @Override
    056    protected double jointEnrollment(JenrlConstraint jenrl) {
    057        return jenrl.jenrl() * jenrl.jenrl();
    058    }
    059
    060    @Override
    061    public void incJenrl(Assignment<Lecture, Placement> assignment, JenrlConstraint jenrl, double studentWeight, Double conflictPriority, Student student) {
    062        if (isApplicable(jenrl.first(), jenrl.second()) && inConflict(assignment.getValue(jenrl.first()), assignment.getValue(jenrl.second()))) {
    063            inc(assignment, (jenrl.jenrl() * jenrl.jenrl()) - (jenrl.jenrl() - studentWeight) * (jenrl.jenrl() - studentWeight));
    064        }
    065    }
    066
    067}