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 Tomáš Müller<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        if (iLastWorkDay < iFirstWorkDay) iLastWorkDay += 7;
062    }
063    
064    @Override
065    public double getWeightDefault(DataProperties config) {
066        return Constants.sPreferenceLevelDiscouraged * config.getPropertyDouble("Comparator.UselessSlotWeight", 0.1);
067    }
068    
069    @Override
070    public String getPlacementSelectionWeightName() {
071        return "Placement.UselessSlotsWeight";
072    }
073    
074    protected double penalty(Assignment<Lecture, Placement> assignment, Placement value) {
075        if (value.isMultiRoom()) {
076            int ret = 0;
077            for (RoomLocation r : value.getRoomLocations()) {
078                if (r.getRoomConstraint() == null)
079                    continue;
080                ret += penalty(r.getRoomConstraint().getContext(assignment), value);
081            }
082            return ret;
083        } else {
084            return (value.getRoomLocation().getRoomConstraint() == null ? 0 : penalty(value.getRoomLocation().getRoomConstraint().getContext(assignment), value));
085        }
086    }
087    
088    protected double penalty(RoomConstraintContext rc) {
089        return countUselessSlotsBrokenTimePatterns(rc) / 6.0;
090    }
091    
092    protected double penalty(RoomConstraintContext rc, Placement value) {
093        return countUselessSlotsBrokenTimePatterns(rc, value) / 6.0;
094    }
095
096   @Override
097    public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
098        double ret = penalty(assignment, value);
099        if (conflicts != null)
100            for (Placement conflict: conflicts)
101                ret -= penalty(assignment, conflict);
102        return ret;
103    }
104    
105    @Override
106    public double getValue(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
107        double ret = 0;
108        Set<RoomConstraint> constraints = new HashSet<RoomConstraint>();
109        for (Lecture lect: variables) {
110            Placement placement = assignment.getValue(lect);
111            if (placement == null) continue;
112            if (placement.isMultiRoom()) {
113                for (RoomLocation r : placement.getRoomLocations()) {
114                    if (r.getRoomConstraint() != null && constraints.add(r.getRoomConstraint()))
115                        ret += penalty(r.getRoomConstraint().getContext(assignment));
116                }
117            } else if (placement.getRoomLocation().getRoomConstraint() != null && 
118                    constraints.add(placement.getRoomLocation().getRoomConstraint())) {
119                ret += penalty(placement.getRoomLocation().getRoomConstraint().getContext(assignment));
120            }
121        }
122        return ret;
123    }
124    
125    @Override
126    protected double[] computeBounds(Assignment<Lecture, Placement> assignment) {
127        return new double[] {
128                ((TimetableModel)getModel()).getRoomConstraints().size() * (iLastWorkDay - iFirstWorkDay + 1) * (iLastDaySlot - iFirstDaySlot + 1),
129                0.0 };
130    }
131    
132    @Override
133    public double[] getBounds(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
134        Set<RoomConstraint> constraints = new HashSet<RoomConstraint>();
135        for (Lecture lect: variables) {
136            Placement placement = assignment.getValue(lect);
137            if (placement == null) continue;
138            if (placement.isMultiRoom()) {
139                for (RoomLocation r : placement.getRoomLocations()) {
140                    if (r.getRoomConstraint() != null)
141                        constraints.add(r.getRoomConstraint());
142                }
143            } else if (placement.getRoomLocation().getRoomConstraint() != null) {
144                constraints.add(placement.getRoomLocation().getRoomConstraint());
145            }
146        }
147        return new double[] {
148                constraints.size() * (iLastWorkDay - iFirstWorkDay + 1) * (iLastDaySlot - iFirstDaySlot + 1),
149                0.0 };
150    }
151    
152    private static int sDaysMWF = Constants.DAY_CODES[0] + Constants.DAY_CODES[2] + Constants.DAY_CODES[4];
153    private static int sDaysTTh = Constants.DAY_CODES[1] + Constants.DAY_CODES[3];
154    
155    private static boolean isEmpty(RoomConstraintContext rc, int s, int d, Placement placement) {
156        List<Placement> assigned = rc.getPlacements(d * Constants.SLOTS_PER_DAY + s);
157        return assigned.isEmpty() || (placement != null && assigned.size() == 1 && assigned.get(0).variable().equals(placement.variable()));
158    }
159
160    /** Number of broken time patterns for this room 
161     * @param rc room constraint
162     * @param placement placement that is being considered
163     * @return number of broken time patterns caused by the given placement
164     **/
165    protected static int countUselessSlotsBrokenTimePatterns(RoomConstraintContext rc, Placement placement) {
166        int ret = 0;
167        TimeLocation time = placement.getTimeLocation();
168        int slot = time.getStartSlot() % Constants.SLOTS_PER_DAY;
169        int days = time.getDayCode();
170        if ((days & sDaysMWF) != 0 && (days & sDaysMWF) != sDaysMWF) {
171            for (int s = slot; s < slot + time.getLength(); s++) {
172                int d = (days & sDaysMWF);
173                if (d == Constants.DAY_CODES[0] && isEmpty(rc, s, 0, placement)) {
174                    if (isEmpty(rc, s, 2, placement) != isEmpty(rc, s, 4, placement)) ret ++;
175                    if (!isEmpty(rc, s, 2, placement) && !isEmpty(rc, s, 4, placement)) ret --;
176                } else if (d == Constants.DAY_CODES[2] && isEmpty(rc, s, 2, placement)) {
177                    if (isEmpty(rc, s, 0, placement) != isEmpty(rc, s, 4, placement)) ret ++;
178                    if (!isEmpty(rc, s, 0, placement) && !isEmpty(rc, s, 4, placement)) ret --;
179                } else if (d == Constants.DAY_CODES[4] && isEmpty(rc, s, 4, placement)) {
180                    if (isEmpty(rc, s, 0, placement) != isEmpty(rc, s, 2, placement)) ret ++;
181                    if (!isEmpty(rc, s, 0, placement) && !isEmpty(rc, s, 2, placement)) ret --;
182                } else if (d == (Constants.DAY_CODES[0] | Constants.DAY_CODES[2]) && isEmpty(rc, s, 0, placement) && isEmpty(rc, s, 2, placement)) {
183                    if (isEmpty(rc, s, 4, placement)) ret ++;
184                } else if (d == (Constants.DAY_CODES[2] | Constants.DAY_CODES[4]) && isEmpty(rc, s, 2, placement) && isEmpty(rc, s, 4, placement)) {
185                    if (isEmpty(rc, s, 0, placement)) ret ++;
186                } else if (d == (Constants.DAY_CODES[0] | Constants.DAY_CODES[4]) && isEmpty(rc, s, 0, placement) && isEmpty(rc, s, 4, placement)) {
187                    if (isEmpty(rc, s, 2, placement)) ret ++;
188                }
189            }
190        }
191        if ((days & sDaysTTh) != 0 && (days & sDaysTTh) != sDaysTTh) {
192            for (int s = slot; s < slot + time.getLength(); s++) {
193                if (isEmpty(rc, s, 1, placement) && isEmpty(rc, s, 3, placement)) ret ++;
194                int d = (days & sDaysTTh);
195                if (d == Constants.DAY_CODES[1] && isEmpty(rc, s, 1, placement) && !isEmpty(rc, s, 3, placement)) ret --;
196                if (d == Constants.DAY_CODES[3] && isEmpty(rc, s, 3, placement) && !isEmpty(rc, s, 1, placement)) ret --;
197            }
198        }
199        return ret;
200    }
201    
202    /** Number of useless slots for this room 
203     * @param rc room constraint
204     * @return current penalty for the given room
205     **/
206    public static int countUselessSlotsBrokenTimePatterns(RoomConstraintContext rc) {
207        int ret = 0;
208        for (int d = 0; d < Constants.NR_DAYS; d++) {
209            for (int s = 0; s < Constants.SLOTS_PER_DAY; s++) {
210                int slot = d * Constants.SLOTS_PER_DAY + s;
211                if (rc.getPlacements(slot).isEmpty()) {
212                    switch (d) {
213                        case 0:
214                            if (!rc.getPlacements(2 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getPlacements(4 * Constants.SLOTS_PER_DAY + s).isEmpty())
215                                ret++;
216                            break;
217                        case 1:
218                            if (!rc.getPlacements(3 * Constants.SLOTS_PER_DAY + s).isEmpty())
219                                ret++;
220                            break;
221                        case 2:
222                            if (!rc.getPlacements(0 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getPlacements(4 * Constants.SLOTS_PER_DAY + s).isEmpty())
223                                ret++;
224                            break;
225                        case 3:
226                            if (!rc.getPlacements(1 * Constants.SLOTS_PER_DAY + s).isEmpty())
227                                ret++;
228                            break;
229                        case 4:
230                            if (!rc.getPlacements(0 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getPlacements(2 * Constants.SLOTS_PER_DAY + s).isEmpty())
231                                ret++;
232                            break;
233                    }
234                }
235            }
236        }
237        return ret;
238    }
239}