001 package net.sf.cpsolver.exam.criteria;
002
003 import java.util.Set;
004
005 import net.sf.cpsolver.exam.model.Exam;
006 import net.sf.cpsolver.exam.model.ExamInstructor;
007 import net.sf.cpsolver.exam.model.ExamPeriod;
008 import net.sf.cpsolver.exam.model.ExamPlacement;
009 import net.sf.cpsolver.ifs.util.DataProperties;
010
011 /**
012 * Number of back-to-back instructor conflicts. I.e., number of cases when
013 * an exam is attended by an instructor that attends some other exam at
014 * the previous {@link ExamPeriod#prev()} or following
015 * {@link ExamPeriod#next()} period. If
016 * {@link StudentBackToBackConflicts#isDayBreakBackToBack()} is false, back-to-back conflicts
017 * are only considered between consecutive periods that are of the same day.
018 * <br><br>
019 * Back-to-back instructor conflict weight can be set by problem property
020 * Exams.InstructorBackToBackConflictWeight, or in the input xml file,
021 * property instructorBackToBackConflictWeight.
022 *
023 *
024 * <br>
025 *
026 * @version ExamTT 1.2 (Examination Timetabling)<br>
027 * Copyright (C) 2008 - 2012 Tomas Muller<br>
028 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
029 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
030 * <br>
031 * This library is free software; you can redistribute it and/or modify
032 * it under the terms of the GNU Lesser General Public License as
033 * published by the Free Software Foundation; either version 3 of the
034 * License, or (at your option) any later version. <br>
035 * <br>
036 * This library is distributed in the hope that it will be useful, but
037 * WITHOUT ANY WARRANTY; without even the implied warranty of
038 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
039 * Lesser General Public License for more details. <br>
040 * <br>
041 * You should have received a copy of the GNU Lesser General Public
042 * License along with this library; if not see
043 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
044 */
045 public class InstructorBackToBackConflicts extends StudentBackToBackConflicts {
046
047 @Override
048 public String getWeightName() {
049 return "Exams.InstructorBackToBackConflictWeight";
050 }
051
052 @Override
053 public String getXmlWeightName() {
054 return "instructorBackToBackConflictWeight";
055 }
056
057 @Override
058 public double getWeightDefault(DataProperties config) {
059 return 10.0;
060 }
061
062 @Override
063 public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
064 Exam exam = value.variable();
065 int penalty = 0;
066 for (ExamInstructor s : exam.getInstructors()) {
067 if (value.getPeriod().prev() != null) {
068 if (isDayBreakBackToBack() || value.getPeriod().prev().getDay() == value.getPeriod().getDay()) {
069 Set<Exam> exams = s.getExams(value.getPeriod().prev());
070 int nrExams = exams.size() + (exams.contains(exam) ? -1 : 0);
071 penalty += nrExams;
072 }
073 }
074 if (value.getPeriod().next() != null) {
075 if (isDayBreakBackToBack() || value.getPeriod().next().getDay() == value.getPeriod().getDay()) {
076 Set<Exam> exams = s.getExams(value.getPeriod().next());
077 int nrExams = exams.size() + (exams.contains(exam) ? -1 : 0);
078 penalty += nrExams;
079 }
080 }
081 }
082 return penalty;
083 }
084
085 @Override
086 public String getName() {
087 return "Instructor Back-To-Back Conflicts";
088 }
089
090 @Override
091 public String toString() {
092 return "iBTB:" + sDoubleFormat.format(getValue());
093 }
094
095 }