001package org.cpsolver.exam.criteria; 002 003import java.util.Map; 004import java.util.Set; 005 006import org.cpsolver.exam.model.Exam; 007import org.cpsolver.exam.model.ExamInstructor; 008import org.cpsolver.exam.model.ExamModel; 009import org.cpsolver.exam.model.ExamPeriod; 010import org.cpsolver.exam.model.ExamPlacement; 011import org.cpsolver.ifs.assignment.Assignment; 012import org.cpsolver.ifs.util.DataProperties; 013 014 015/** 016 * Number of back-to-back instructor conflicts. I.e., number of cases when 017 * an exam is attended by an instructor that attends some other exam at 018 * the previous {@link ExamPeriod#prev()} or following 019 * {@link ExamPeriod#next()} period. If 020 * {@link StudentBackToBackConflicts#isDayBreakBackToBack()} is false, back-to-back conflicts 021 * are only considered between consecutive periods that are of the same day. 022 * <br><br> 023 * Back-to-back instructor conflict weight can be set by problem property 024 * Exams.InstructorBackToBackConflictWeight, or in the input xml file, 025 * property instructorBackToBackConflictWeight. 026 * 027 * 028 * <br> 029 * 030 * @version ExamTT 1.3 (Examination Timetabling)<br> 031 * Copyright (C) 2008 - 2014 Tomáš Müller<br> 032 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 033 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 034 * <br> 035 * This library is free software; you can redistribute it and/or modify 036 * it under the terms of the GNU Lesser General Public License as 037 * published by the Free Software Foundation; either version 3 of the 038 * License, or (at your option) any later version. <br> 039 * <br> 040 * This library is distributed in the hope that it will be useful, but 041 * WITHOUT ANY WARRANTY; without even the implied warranty of 042 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 043 * Lesser General Public License for more details. <br> 044 * <br> 045 * You should have received a copy of the GNU Lesser General Public 046 * License along with this library; if not see 047 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 048 */ 049public class InstructorBackToBackConflicts extends StudentBackToBackConflicts { 050 051 @Override 052 public String getWeightName() { 053 return "Exams.InstructorBackToBackConflictWeight"; 054 } 055 056 @Override 057 public String getXmlWeightName() { 058 return "instructorBackToBackConflictWeight"; 059 } 060 061 @Override 062 public double getWeightDefault(DataProperties config) { 063 return 10.0; 064 } 065 066 @Override 067 public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) { 068 Exam exam = value.variable(); 069 int penalty = 0; 070 ExamPeriod period = value.getPeriod(); 071 Map<ExamInstructor, Set<Exam>> prev = (period.prev() != null && (isDayBreakBackToBack() || period.prev().getDay() == period.getDay()) ? ((ExamModel)getModel()).getInstructorsOfPeriod(assignment, period.prev()) : null); 072 Map<ExamInstructor, Set<Exam>> next = (period.next() != null && (isDayBreakBackToBack() || period.next().getDay() == period.getDay()) ? ((ExamModel)getModel()).getInstructorsOfPeriod(assignment, period.next()) : null); 073 for (ExamInstructor s : exam.getInstructors()) { 074 if (prev != null) { 075 Set<Exam> exams = prev.get(s); 076 if (exams != null) { 077 int nrExams = exams.size() + (exams.contains(exam) ? -1 : 0); 078 penalty += nrExams; 079 } 080 } 081 if (next != null) { 082 Set<Exam> exams = next.get(s); 083 if (exams != null) { 084 int nrExams = exams.size() + (exams.contains(exam) ? -1 : 0); 085 penalty += nrExams; 086 } 087 } 088 } 089 /* 090 for (ExamInstructor s : exam.getInstructors()) { 091 if (period.prev() != null) { 092 if (isDayBreakBackToBack() || period.prev().getDay() == period.getDay()) { 093 Set<Exam> exams = s.getExams(assignment, period.prev()); 094 int nrExams = exams.size() + (exams.contains(exam) ? -1 : 0); 095 penalty += nrExams; 096 } 097 } 098 if (period.next() != null) { 099 if (isDayBreakBackToBack() || period.next().getDay() == period.getDay()) { 100 Set<Exam> exams = s.getExams(assignment, period.next()); 101 int nrExams = exams.size() + (exams.contains(exam) ? -1 : 0); 102 penalty += nrExams; 103 } 104 } 105 } 106 */ 107 return penalty; 108 } 109 110 @Override 111 public String getName() { 112 return "Instructor Back-To-Back Conflicts"; 113 } 114 115 @Override 116 public String toString(Assignment<Exam, ExamPlacement> assignment) { 117 return "iBTB:" + sDoubleFormat.format(getValue(assignment)); 118 } 119 120}