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