001    package net.sf.cpsolver.coursett.criteria.additional;
002    
003    import java.util.Collection;
004    import java.util.Map;
005    
006    import net.sf.cpsolver.coursett.constraint.JenrlConstraint;
007    import net.sf.cpsolver.coursett.model.Lecture;
008    import net.sf.cpsolver.coursett.model.Student;
009    import net.sf.cpsolver.ifs.util.DataProperties;
010    
011    /**
012     * Instructor student conflicts. This criterion penalizes cases when an instructor (of a class) is attending some 
013     * other class as a student and there is a conflict between the two classes. Also, there is no alternative for the
014     * student class (the conflict cannot be sectioned away).
015     * <br>
016     * To enable instructor student conflicts, set solver parameter Global.LoadStudentInstructorConflicts to true. Also
017     * student course requests should be used in this case (to be able to match an instructor external id to a student 
018     * external id).
019     * <br>
020     * Hard instructor student conflicts are weighted by Comparator.InstructorHardStudentConflictWeight.
021     * <br>
022     * 
023     * @version CourseTT 1.2 (University Course Timetabling)<br>
024     *          Copyright (C) 2006 - 2011 Tomas Muller<br>
025     *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
026     *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
027     * <br>
028     *          This library is free software; you can redistribute it and/or modify
029     *          it under the terms of the GNU Lesser General Public License as
030     *          published by the Free Software Foundation; either version 3 of the
031     *          License, or (at your option) any later version. <br>
032     * <br>
033     *          This library is distributed in the hope that it will be useful, but
034     *          WITHOUT ANY WARRANTY; without even the implied warranty of
035     *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
036     *          Lesser General Public License for more details. <br>
037     * <br>
038     *          You should have received a copy of the GNU Lesser General Public
039     *          License along with this library; if not see
040     *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
041     */
042    public class InstructorStudentHardConflict extends InstructorStudentConflict {
043        
044        @Override
045        public boolean isApplicable(Lecture l1, Lecture l2) {
046            return super.isApplicable(l1, l2) && oneInstructorOtherHard(l1, l2);
047        }
048        
049        /**
050         * One of the lectures is hard, there is a joint enrollment constraint between them, and 
051         * there is at least one student that is instructor for one lecture and the other lecture
052         * is singleton.
053         */
054        public static boolean oneInstructorOtherHard(Lecture l1, Lecture l2) {
055            if (!hard(l1, l2)) return false;
056            JenrlConstraint jenrl = l1.jenrlConstraint(l2);
057            if (jenrl == null) return false;
058            for (Student student: jenrl.getInstructors()) {
059                if ((l1.isSingleSection() || student.getInstructor().variables().contains(jenrl.second())) &&
060                    (l2.isSingleSection() || student.getInstructor().variables().contains(jenrl.first())))
061                    return true;
062            }
063            return false;
064        }
065    
066        @Override
067        public double getWeightDefault(DataProperties config) {
068            return config.getPropertyDouble("Comparator.InstructorHardStudentConflictWeight", 10.0 * config.getPropertyDouble("Comparator.HardStudentConflictWeight", 5.0));
069        }
070        
071        @Override
072        public String getPlacementSelectionWeightName() {
073            return "Placement.NrInstructorHardStudConfsWeight";
074        }
075        
076        @Override
077        public void getInfo(Map<String, String> info) {
078        }
079        
080        @Override
081        public void getInfo(Map<String, String> info, Collection<Lecture> variables) {
082        }
083    
084    }