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; 009 010/** 011 * Fix initial assignment constraint. This global constraint checks that the 012 * conflicts that have been computed so far (by other global constraints earlier 013 * in the list) do not create a conflict with an initial assignment. This constraint 014 * is to be used only when MPP is enabled and it is to be last global constraint 015 * in the list. 016 * 017 * @version StudentSct 1.3 (Student Sectioning)<br> 018 * Copyright (C) 2007 - 2015 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 FixInitialAssignments extends GlobalConstraint<Request, Enrollment> { 037 038 /** 039 * If there is a conflict that is MPP (method {@link Request#isMPP()} returns true) 040 * and equal to the initial assignment (returned by {@link Request#getInitialAssignment()}), 041 * the given enrollment is put into the conflicts. 042 */ 043 @Override 044 public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollment enrollment, Set<Enrollment> conflicts) { 045 for (Enrollment conflict: conflicts) 046 if (conflict.getRequest().isMPP() && conflict.equals(conflict.getRequest().getInitialAssignment())) { 047 conflicts.add(enrollment); 048 return; 049 } 050 } 051}