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