    001package org.cpsolver.instructor.criteria;
    002
    003import java.util.Collection;
    004import java.util.HashSet;
    005import java.util.Set;
    006
    007import org.cpsolver.ifs.assignment.Assignment;
    008import org.cpsolver.ifs.util.DataProperties;
    009import org.cpsolver.instructor.model.Instructor;
    010import org.cpsolver.instructor.model.TeachingAssignment;
    011import org.cpsolver.instructor.model.TeachingRequest;
    012
    013/**
    014 * Unused Instructor Load. If an instructor is being used (has at least one teaching assignment),
    015 * this criterion can penalize the remaining (unused) load of the instructor. That is the difference
    016 * between instructor maximal load and the assigned load of the instructor.
    017 *
    018 * @author  Tomáš Müller
    019 * @version IFS 1.3 (Instructor Sectioning)<br>
    020 *          Copyright (C) 2016 Tomáš Müller<br>
    021 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    022 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    023 * <br>
    024 *          This library is free software; you can redistribute it and/or modify
    025 *          it under the terms of the GNU Lesser General Public License as
    026 *          published by the Free Software Foundation; either version 3 of the
    027 *          License, or (at your option) any later version. <br>
    028 * <br>
    029 *          This library is distributed in the hope that it will be useful, but
    030 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    031 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    032 *          Lesser General Public License for more details. <br>
    033 * <br>
    034 *          You should have received a copy of the GNU Lesser General Public
    035 *          License along with this library; if not see
    036 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    037 */
    038public class UnusedInstructorLoad extends InstructorSchedulingCriterion {
    039
    040    public UnusedInstructorLoad() {
    041        setValueUpdateType(ValueUpdateType.NoUpdate);
    042    }
    043
    044    @Override
    045    public double getWeightDefault(DataProperties config) {
    046        return 100000.0;
    047    }
    048
    049    @Override
    050    public double getValue(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, TeachingAssignment value, Set<TeachingAssignment> conflicts) {
    051        Instructor.Context cx = value.getInstructor().getContext(assignment);
    052
    053        float load = cx.getLoad();
    054        if (!cx.getAssignments().contains(value)) load += value.variable().getRequest().getLoad();
    055        if (conflicts != null)
    056            for (TeachingAssignment ta: conflicts)
    057                if (ta.getInstructor().equals(value.getInstructor())) load -= ta.variable().getRequest().getLoad();
    058
    059        return Math.max(0, value.getInstructor().getMaxLoad() - load);
    060    }
    061
    062    @Override
    063    public double getValue(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, Collection<TeachingRequest.Variable> variables) {
    064        double unused = 0.0;
    065        Set<Instructor> instructors = new HashSet<Instructor>();
    066        for (TeachingRequest.Variable req: variables) {
    067            TeachingAssignment ta = assignment.getValue(req);
    068            if (ta != null &&instructors.add(ta.getInstructor())) {
    069                unused += ta.getInstructor().getMaxLoad() - ta.getInstructor().getContext(assignment).getLoad();
    070            }
    071        }
    072        return unused;
    073    }
    074
    075    @Override
    076    public String getAbbreviation() {
    077        return "UnusedLoad";
    078    }
    079}