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.Request; 009import org.cpsolver.studentsct.model.Section; 010 011 012/** 013 * Cancelled sections constraint. This global constraint ensures that no enrollment 014 * containing a cancelled sections (using {@link Section#isCancelled()}) is used. 015 * 016 * @version StudentSct 1.3 (Student Sectioning)<br> 017 * Copyright (C) 2014 Tomáš Müller<br> 018 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 019 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 020 * <br> 021 * This library is free software; you can redistribute it and/or modify 022 * it under the terms of the GNU Lesser General Public License as 023 * published by the Free Software Foundation; either version 3 of the 024 * License, or (at your option) any later version. <br> 025 * <br> 026 * This library is distributed in the hope that it will be useful, but 027 * WITHOUT ANY WARRANTY; without even the implied warranty of 028 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 029 * Lesser General Public License for more details. <br> 030 * <br> 031 * You should have received a copy of the GNU Lesser General Public 032 * License along with this library; if not see 033 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 034 */ 035public class CancelledSections extends GlobalConstraint<Request, Enrollment> { 036 037 /** 038 * A given enrollment is conflicting, if there is a section that 039 * is cancelled. 040 * 041 * @param enrollment {@link Enrollment} that is being considered 042 * @param conflicts all computed conflicting requests are added into this set 043 */ 044 @Override 045 public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollment enrollment, Set<Enrollment> conflicts) { 046 if (inConflict(assignment, enrollment)) 047 conflicts.add(enrollment); 048 } 049 050 /** 051 * A given enrollment is conflicting, if there is a section that 052 * is cancelled. 053 * 054 * @param enrollment {@link Enrollment} that is being considered 055 * @return true, if the enrollment does not follow a reservation that must be used 056 */ 057 @Override 058 public boolean inConflict(Assignment<Request, Enrollment> assignment, Enrollment enrollment) { 059 // exclude free time requests 060 if (enrollment.getConfig() == null) return false; 061 062 // check all sections of the given enrollment 063 for (Section section: enrollment.getSections()) 064 if (section.isCancelled()) return true; 065 066 return false; 067 } 068 069 @Override 070 public String toString() { 071 return "CancelledSections"; 072 } 073}