001package org.cpsolver.coursett.criteria;
002
003import java.util.Collection;
004import java.util.HashSet;
005import java.util.List;
006import java.util.Set;
007
008import org.cpsolver.coursett.Constants;
009import org.cpsolver.coursett.constraint.RoomConstraint;
010import org.cpsolver.coursett.constraint.RoomConstraint.RoomConstraintContext;
011import org.cpsolver.coursett.model.Lecture;
012import org.cpsolver.coursett.model.Placement;
013import org.cpsolver.coursett.model.RoomLocation;
014import org.cpsolver.coursett.model.TimeLocation;
015import org.cpsolver.coursett.model.TimetableModel;
016import org.cpsolver.ifs.assignment.Assignment;
017import org.cpsolver.ifs.util.DataProperties;
018
019
020/**
021 * Broken time patterns. This criterion counts cases when an unused space is in a room
022 * which follows one of the standard MWF or TTh pattern. E.g., there is a penalty of
023 * Monday is available during a time when Wednesday and/or Friday is occupied. The aim
024 * is to use this space if possible in order to leave the available space in a way that 
025 * can be used by MWF or TTh classes.
026 * <br>
027 * 
028 * @author  Tomáš Müller
029 * @version CourseTT 1.3 (University Course Timetabling)<br>
030 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
031 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
032 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
033 * <br>
034 *          This library is free software; you can redistribute it and/or modify
035 *          it under the terms of the GNU Lesser General Public License as
036 *          published by the Free Software Foundation; either version 3 of the
037 *          License, or (at your option) any later version. <br>
038 * <br>
039 *          This library is distributed in the hope that it will be useful, but
040 *          WITHOUT ANY WARRANTY; without even the implied warranty of
041 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
042 *          Lesser General Public License for more details. <br>
043 * <br>
044 *          You should have received a copy of the GNU Lesser General Public
045 *          License along with this library; if not see
046 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
047 */
048public class BrokenTimePatterns extends TimetablingCriterion {
049    private int iFirstDaySlot, iLastDaySlot, iFirstWorkDay, iLastWorkDay;
050    
051    public BrokenTimePatterns() {
052        setValueUpdateType(ValueUpdateType.NoUpdate);
053    }
054    
055    @Override
056    public void configure(DataProperties properties) {   
057        super.configure(properties);
058        iFirstDaySlot = properties.getPropertyInt("General.FirstDaySlot", Constants.DAY_SLOTS_FIRST);
059        iLastDaySlot = properties.getPropertyInt("General.LastDaySlot", Constants.DAY_SLOTS_LAST);
060        iFirstWorkDay = properties.getPropertyInt("General.FirstWorkDay", 0);
061        iLastWorkDay = properties.getPropertyInt("General.LastWorkDay", Constants.NR_DAYS_WEEK - 1);
062        if (iLastWorkDay < iFirstWorkDay) iLastWorkDay += 7;
063    }
064    
065    @Override
066    public double getWeightDefault(DataProperties config) {
067        return Constants.sPreferenceLevelDiscouraged * config.getPropertyDouble("Comparator.UselessSlotWeight", 0.1);
068    }
069    
070    @Override
071    public String getPlacementSelectionWeightName() {
072        return "Placement.UselessSlotsWeight";
073    }
074    
075    protected double penalty(Assignment<Lecture, Placement> assignment, Placement value) {
076        if (value.isMultiRoom()) {
077            int ret = 0;
078            for (RoomLocation r : value.getRoomLocations()) {
079                if (r.getRoomConstraint() == null)
080                    continue;
081                ret += penalty(r.getRoomConstraint().getContext(assignment), value);
082            }
083            return ret;
084        } else {
085            return (value.getRoomLocation().getRoomConstraint() == null ? 0 : penalty(value.getRoomLocation().getRoomConstraint().getContext(assignment), value));
086        }
087    }
088    
089    protected double penalty(RoomConstraintContext rc) {
090        return countUselessSlotsBrokenTimePatterns(rc) / 6.0;
091    }
092    
093    protected double penalty(RoomConstraintContext rc, Placement value) {
094        return countUselessSlotsBrokenTimePatterns(rc, value) / 6.0;
095    }
096
097   @Override
098    public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
099        double ret = penalty(assignment, value);
100        if (conflicts != null)
101            for (Placement conflict: conflicts)
102                ret -= penalty(assignment, conflict);
103        return ret;
104    }
105    
106    @Override
107    public double getValue(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
108        double ret = 0;
109        Set<RoomConstraint> constraints = new HashSet<RoomConstraint>();
110        for (Lecture lect: variables) {
111            Placement placement = assignment.getValue(lect);
112            if (placement == null) continue;
113            if (placement.isMultiRoom()) {
114                for (RoomLocation r : placement.getRoomLocations()) {
115                    if (r.getRoomConstraint() != null && constraints.add(r.getRoomConstraint()))
116                        ret += penalty(r.getRoomConstraint().getContext(assignment));
117                }
118            } else if (placement.getRoomLocation().getRoomConstraint() != null && 
119                    constraints.add(placement.getRoomLocation().getRoomConstraint())) {
120                ret += penalty(placement.getRoomLocation().getRoomConstraint().getContext(assignment));
121            }
122        }
123        return ret;
124    }
125    
126    @Override
127    protected double[] computeBounds(Assignment<Lecture, Placement> assignment) {
128        return new double[] {
129                ((TimetableModel)getModel()).getRoomConstraints().size() * (iLastWorkDay - iFirstWorkDay + 1) * (iLastDaySlot - iFirstDaySlot + 1),
130                0.0 };
131    }
132    
133    @Override
134    public double[] getBounds(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
135        Set<RoomConstraint> constraints = new HashSet<RoomConstraint>();
136        for (Lecture lect: variables) {
137            Placement placement = assignment.getValue(lect);
138            if (placement == null) continue;
139            if (placement.isMultiRoom()) {
140                for (RoomLocation r : placement.getRoomLocations()) {
141                    if (r.getRoomConstraint() != null)
142                        constraints.add(r.getRoomConstraint());
143                }
144            } else if (placement.getRoomLocation().getRoomConstraint() != null) {
145                constraints.add(placement.getRoomLocation().getRoomConstraint());
146            }
147        }
148        return new double[] {
149                constraints.size() * (iLastWorkDay - iFirstWorkDay + 1) * (iLastDaySlot - iFirstDaySlot + 1),
150                0.0 };
151    }
152    
153    private static int sDaysMWF = Constants.DAY_CODES[0] + Constants.DAY_CODES[2] + Constants.DAY_CODES[4];
154    private static int sDaysTTh = Constants.DAY_CODES[1] + Constants.DAY_CODES[3];
155    
156    private static boolean isEmpty(RoomConstraintContext rc, int s, int d, Placement placement) {
157        List<Placement> assigned = rc.getPlacements(d * Constants.SLOTS_PER_DAY + s);
158        return assigned.isEmpty() || (placement != null && assigned.size() == 1 && assigned.get(0).variable().equals(placement.variable()));
159    }
160
161    /** Number of broken time patterns for this room 
162     * @param rc room constraint
163     * @param placement placement that is being considered
164     * @return number of broken time patterns caused by the given placement
165     **/
166    protected static int countUselessSlotsBrokenTimePatterns(RoomConstraintContext rc, Placement placement) {
167        int ret = 0;
168        TimeLocation time = placement.getTimeLocation();
169        int slot = time.getStartSlot() % Constants.SLOTS_PER_DAY;
170        int days = time.getDayCode();
171        if ((days & sDaysMWF) != 0 && (days & sDaysMWF) != sDaysMWF) {
172            for (int s = slot; s < slot + time.getLength(); s++) {
173                int d = (days & sDaysMWF);
174                if (d == Constants.DAY_CODES[0] && isEmpty(rc, s, 0, placement)) {
175                    if (isEmpty(rc, s, 2, placement) != isEmpty(rc, s, 4, placement)) ret ++;
176                    if (!isEmpty(rc, s, 2, placement) && !isEmpty(rc, s, 4, placement)) ret --;
177                } else if (d == Constants.DAY_CODES[2] && isEmpty(rc, s, 2, placement)) {
178                    if (isEmpty(rc, s, 0, placement) != isEmpty(rc, s, 4, placement)) ret ++;
179                    if (!isEmpty(rc, s, 0, placement) && !isEmpty(rc, s, 4, placement)) ret --;
180                } else if (d == Constants.DAY_CODES[4] && isEmpty(rc, s, 4, placement)) {
181                    if (isEmpty(rc, s, 0, placement) != isEmpty(rc, s, 2, placement)) ret ++;
182                    if (!isEmpty(rc, s, 0, placement) && !isEmpty(rc, s, 2, placement)) ret --;
183                } else if (d == (Constants.DAY_CODES[0] | Constants.DAY_CODES[2]) && isEmpty(rc, s, 0, placement) && isEmpty(rc, s, 2, placement)) {
184                    if (isEmpty(rc, s, 4, placement)) ret ++;
185                } else if (d == (Constants.DAY_CODES[2] | Constants.DAY_CODES[4]) && isEmpty(rc, s, 2, placement) && isEmpty(rc, s, 4, placement)) {
186                    if (isEmpty(rc, s, 0, placement)) ret ++;
187                } else if (d == (Constants.DAY_CODES[0] | Constants.DAY_CODES[4]) && isEmpty(rc, s, 0, placement) && isEmpty(rc, s, 4, placement)) {
188                    if (isEmpty(rc, s, 2, placement)) ret ++;
189                }
190            }
191        }
192        if ((days & sDaysTTh) != 0 && (days & sDaysTTh) != sDaysTTh) {
193            for (int s = slot; s < slot + time.getLength(); s++) {
194                if (isEmpty(rc, s, 1, placement) && isEmpty(rc, s, 3, placement)) ret ++;
195                int d = (days & sDaysTTh);
196                if (d == Constants.DAY_CODES[1] && isEmpty(rc, s, 1, placement) && !isEmpty(rc, s, 3, placement)) ret --;
197                if (d == Constants.DAY_CODES[3] && isEmpty(rc, s, 3, placement) && !isEmpty(rc, s, 1, placement)) ret --;
198            }
199        }
200        return ret;
201    }
202    
203    /** Number of useless slots for this room 
204     * @param rc room constraint
205     * @return current penalty for the given room
206     **/
207    public static int countUselessSlotsBrokenTimePatterns(RoomConstraintContext rc) {
208        int ret = 0;
209        for (int d = 0; d < Constants.NR_DAYS; d++) {
210            for (int s = 0; s < Constants.SLOTS_PER_DAY; s++) {
211                int slot = d * Constants.SLOTS_PER_DAY + s;
212                if (rc.getPlacements(slot).isEmpty()) {
213                    switch (d) {
214                        case 0:
215                            if (!rc.getPlacements(2 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getPlacements(4 * Constants.SLOTS_PER_DAY + s).isEmpty())
216                                ret++;
217                            break;
218                        case 1:
219                            if (!rc.getPlacements(3 * Constants.SLOTS_PER_DAY + s).isEmpty())
220                                ret++;
221                            break;
222                        case 2:
223                            if (!rc.getPlacements(0 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getPlacements(4 * Constants.SLOTS_PER_DAY + s).isEmpty())
224                                ret++;
225                            break;
226                        case 3:
227                            if (!rc.getPlacements(1 * Constants.SLOTS_PER_DAY + s).isEmpty())
228                                ret++;
229                            break;
230                        case 4:
231                            if (!rc.getPlacements(0 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getPlacements(2 * Constants.SLOTS_PER_DAY + s).isEmpty())
232                                ret++;
233                            break;
234                    }
235                }
236            }
237        }
238        return ret;
239    }
240}