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