    001package org.cpsolver.studentsct.constraint;
    002
    003import java.util.Set;
    004
    005import org.cpsolver.ifs.assignment.Assignment;
    006import org.cpsolver.ifs.model.GlobalConstraint;
    007import org.cpsolver.studentsct.model.Enrollment;
    008import org.cpsolver.studentsct.model.FreeTimeRequest;
    009import org.cpsolver.studentsct.model.Request;
    010import org.cpsolver.studentsct.model.Student;
    011
    012/**
    013 * A simple global constraint that does not allow an overlap with a higher
    014 * priority free time request, even when it is not assigned.
    015 *
    016 * @author  Tomáš Müller
    017 * @version StudentSct 1.3 (Student Sectioning)<br>
    018 *          Copyright (C) 2007 - 2026 Tomáš Müller<br>
    019 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    020 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    021 * <br>
    022 *          This library is free software; you can redistribute it and/or modify
    023 *          it under the terms of the GNU Lesser General Public License as
    024 *          published by the Free Software Foundation; either version 3 of the
    025 *          License, or (at your option) any later version. <br>
    026 * <br>
    027 *          This library is distributed in the hope that it will be useful, but
    028 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    029 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    030 *          Lesser General Public License for more details. <br>
    031 * <br>
    032 *          You should have received a copy of the GNU Lesser General Public
    033 *          License along with this library; if not see
    034 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    035 */
    036public class FreeTimeConflicts extends GlobalConstraint<Request, Enrollment> {
    037
    038    @Override
    039    public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollment value, Set<Enrollment> conflicts) {
    040        if (inConflict(assignment, value)) conflicts.add(value);
    041    }
    042
    043    @Override
    044    public boolean inConflict(Assignment<Request, Enrollment> assignment, Enrollment value) {
    045        if (value.isAllowOverlap()) return false;
    046        Student student = value.getRequest().getStudent();
    047        for (Request request: student.getRequests()) {
    048            if (request.equals(value.getRequest())) break;
    049            if (request instanceof FreeTimeRequest) {
    050                FreeTimeRequest ft = (FreeTimeRequest)request;
    051                if (ft.isOverlapping(value.getSections())) return true;
    052            }
    053        }
    054        return false;
    055    }
    056
    057}