001    package net.sf.cpsolver.coursett.criteria.additional;
002    
003    import net.sf.cpsolver.coursett.constraint.JenrlConstraint;
004    import net.sf.cpsolver.coursett.criteria.StudentConflict;
005    import net.sf.cpsolver.coursett.model.Lecture;
006    import net.sf.cpsolver.coursett.model.Student;
007    import net.sf.cpsolver.ifs.util.DataProperties;
008    
009    /**
010     * Quadratic student conflicts. Same as {@link StudentConflict}, however,
011     * student joint enrollments are squared (1 conflict counts as 1, 2 as 4, 3 as 9, etc.).
012     * 
013     * <br>
014     * 
015     * @version CourseTT 1.2 (University Course Timetabling)<br>
016     *          Copyright (C) 2006 - 2011 Tomas Muller<br>
017     *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
018     *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
019     * <br>
020     *          This library is free software; you can redistribute it and/or modify
021     *          it under the terms of the GNU Lesser General Public License as
022     *          published by the Free Software Foundation; either version 3 of the
023     *          License, or (at your option) any later version. <br>
024     * <br>
025     *          This library is distributed in the hope that it will be useful, but
026     *          WITHOUT ANY WARRANTY; without even the implied warranty of
027     *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
028     *          Lesser General Public License for more details. <br>
029     * <br>
030     *          You should have received a copy of the GNU Lesser General Public
031     *          License along with this library; if not see
032     *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
033     */
034    
035    public class QuadraticStudentConflict extends StudentConflict {
036        
037        @Override
038        public boolean isApplicable(Lecture l1, Lecture l2) {
039            return applicable(l1, l2);
040        }
041    
042        @Override
043        public double getWeightDefault(DataProperties config) {
044            return config.getPropertyDouble("Comparator.StudentConflictWeight", 1.0);
045        }
046        
047        @Override
048        public String getPlacementSelectionWeightName() {
049            return "Placement.NrStudConfsWeight";
050        }
051    
052        @Override
053        protected double jointEnrollment(JenrlConstraint jenrl) {
054            return jenrl.jenrl() * jenrl.jenrl();
055        }
056        
057        @Override
058        public void incJenrl(JenrlConstraint jenrl, double studentWeight, Double conflictPriority, Student student) {
059            if (inConflict(jenrl.first().getAssignment(), jenrl.second().getAssignment())) {
060                iValue += (jenrl.jenrl() * jenrl.jenrl()) - (jenrl.jenrl() - studentWeight) * (jenrl.jenrl() - studentWeight);
061            }
062        }
063        
064    }