001package net.sf.cpsolver.coursett.criteria;
002
003import java.util.Collection;
004import java.util.HashSet;
005import java.util.List;
006import java.util.Set;
007
008import net.sf.cpsolver.coursett.Constants;
009import net.sf.cpsolver.coursett.constraint.RoomConstraint;
010import net.sf.cpsolver.coursett.model.Lecture;
011import net.sf.cpsolver.coursett.model.Placement;
012import net.sf.cpsolver.coursett.model.RoomLocation;
013import net.sf.cpsolver.coursett.model.TimeLocation;
014import net.sf.cpsolver.coursett.model.TimetableModel;
015import net.sf.cpsolver.ifs.util.DataProperties;
016
017/**
018 * Broken time patterns. This criterion counts cases when an unused space is in a room
019 * which follows one of the standard MWF or TTh pattern. E.g., there is a penalty of
020 * Monday is available during a time when Wednesday and/or Friday is occupied. The aim
021 * is to use this space if possible in order to leave the available space in a way that 
022 * can be used by MWF or TTh classes.
023 * <br>
024 * 
025 * @version CourseTT 1.2 (University Course Timetabling)<br>
026 *          Copyright (C) 2006 - 2011 Tomáš Müller<br>
027 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
028 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
029 * <br>
030 *          This library is free software; you can redistribute it and/or modify
031 *          it under the terms of the GNU Lesser General Public License as
032 *          published by the Free Software Foundation; either version 3 of the
033 *          License, or (at your option) any later version. <br>
034 * <br>
035 *          This library is distributed in the hope that it will be useful, but
036 *          WITHOUT ANY WARRANTY; without even the implied warranty of
037 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
038 *          Lesser General Public License for more details. <br>
039 * <br>
040 *          You should have received a copy of the GNU Lesser General Public
041 *          License along with this library; if not see
042 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
043 */
044public class BrokenTimePatterns extends TimetablingCriterion {
045    
046    public BrokenTimePatterns() {
047        iValueUpdateType = ValueUpdateType.NoUpdate;
048    }
049    
050    @Override
051    public double getWeightDefault(DataProperties config) {
052        return Constants.sPreferenceLevelDiscouraged * config.getPropertyDouble("Comparator.UselessSlotWeight", 0.1);
053    }
054    
055    @Override
056    public String getPlacementSelectionWeightName() {
057        return "Placement.UselessSlotsWeight";
058    }
059    
060    protected double penalty(Placement value) {
061        if (value.isMultiRoom()) {
062            int ret = 0;
063            for (RoomLocation r : value.getRoomLocations()) {
064                if (r.getRoomConstraint() == null)
065                    continue;
066                ret += penalty(r.getRoomConstraint(), value);
067            }
068            return ret;
069        } else {
070            return (value.getRoomLocation().getRoomConstraint() == null ? 0 : penalty(value.getRoomLocation().getRoomConstraint(), value));
071        }
072    }
073    
074    protected double penalty(RoomConstraint rc) {
075        return countUselessSlotsBrokenTimePatterns(rc) / 6.0;
076    }
077    
078   protected double penalty(RoomConstraint rc, Placement value) {
079        return countUselessSlotsBrokenTimePatterns(rc, value) / 6.0;
080    }
081
082   @Override
083    public double getValue(Placement value, Set<Placement> conflicts) {
084        double ret = penalty(value);
085        if (conflicts != null)
086            for (Placement conflict: conflicts)
087                ret -= penalty(conflict);
088        return ret;
089    }
090    
091    @Override
092    public double getValue(Collection<Lecture> variables) {
093        double ret = 0;
094        Set<RoomConstraint> constraints = new HashSet<RoomConstraint>();
095        for (Lecture lect: variables) {
096            if (lect.getAssignment() == null) continue;
097            if (lect.getAssignment().isMultiRoom()) {
098                for (RoomLocation r : lect.getAssignment().getRoomLocations()) {
099                    if (r.getRoomConstraint() != null && constraints.add(r.getRoomConstraint()))
100                        ret += penalty(r.getRoomConstraint());
101                }
102            } else if (lect.getAssignment().getRoomLocation().getRoomConstraint() != null && 
103                    constraints.add(lect.getAssignment().getRoomLocation().getRoomConstraint())) {
104                ret += penalty(lect.getAssignment().getRoomLocation().getRoomConstraint());
105            }
106        }
107        return ret;
108    }
109    
110    @Override
111    protected double[] computeBounds() {
112        return new double[] {
113                ((TimetableModel)getModel()).getRoomConstraints().size() * Constants.SLOTS_PER_DAY_NO_EVENINGS * Constants.NR_DAYS_WEEK,
114                0.0
115        };
116    }
117    
118    @Override
119    public double[] getBounds(Collection<Lecture> variables) {
120        Set<RoomConstraint> constraints = new HashSet<RoomConstraint>();
121        for (Lecture lect: variables) {
122            if (lect.getAssignment() == null) continue;
123            if (lect.getAssignment().isMultiRoom()) {
124                for (RoomLocation r : lect.getAssignment().getRoomLocations()) {
125                    if (r.getRoomConstraint() != null)
126                        constraints.add(r.getRoomConstraint());
127                }
128            } else if (lect.getAssignment().getRoomLocation().getRoomConstraint() != null) {
129                constraints.add(lect.getAssignment().getRoomLocation().getRoomConstraint());
130            }
131        }
132        return new double[] {
133                constraints.size() * Constants.SLOTS_PER_DAY_NO_EVENINGS * Constants.NR_DAYS_WEEK,
134                0.0 };
135    }
136    
137    private static int sDaysMWF = Constants.DAY_CODES[0] + Constants.DAY_CODES[2] + Constants.DAY_CODES[4];
138    private static int sDaysTTh = Constants.DAY_CODES[1] + Constants.DAY_CODES[3];
139    
140    private static boolean isEmpty(RoomConstraint rc, int s, int d, Placement placement) {
141        List<Placement> assigned = rc.getResource(d * Constants.SLOTS_PER_DAY + s);
142        return assigned.isEmpty() || (placement != null && assigned.size() == 1 && assigned.get(0).variable().equals(placement.variable()));
143    }
144
145    /** Number of broken time patterns for this room */
146    protected static int countUselessSlotsBrokenTimePatterns(RoomConstraint rc, Placement placement) {
147        int ret = 0;
148        TimeLocation time = placement.getTimeLocation();
149        int slot = time.getStartSlot() % Constants.SLOTS_PER_DAY;
150        int days = time.getDayCode();
151        if ((days & sDaysMWF) != 0 && (days & sDaysMWF) != sDaysMWF) {
152            for (int s = slot; s < slot + time.getLength(); s++) {
153                int d = (days & sDaysMWF);
154                if (d == Constants.DAY_CODES[0] && isEmpty(rc, s, 0, placement)) {
155                    if (isEmpty(rc, s, 2, placement) != isEmpty(rc, s, 4, placement)) ret ++;
156                    if (!isEmpty(rc, s, 2, placement) && !isEmpty(rc, s, 4, placement)) ret --;
157                } else if (d == Constants.DAY_CODES[2] && isEmpty(rc, s, 2, placement)) {
158                    if (isEmpty(rc, s, 0, placement) != isEmpty(rc, s, 4, placement)) ret ++;
159                    if (!isEmpty(rc, s, 0, placement) && !isEmpty(rc, s, 4, placement)) ret --;
160                } else if (d == Constants.DAY_CODES[4] && isEmpty(rc, s, 4, placement)) {
161                    if (isEmpty(rc, s, 0, placement) != isEmpty(rc, s, 2, placement)) ret ++;
162                    if (!isEmpty(rc, s, 0, placement) && !isEmpty(rc, s, 2, placement)) ret --;
163                } else if (d == (Constants.DAY_CODES[0] | Constants.DAY_CODES[2]) && isEmpty(rc, s, 0, placement) && isEmpty(rc, s, 2, placement)) {
164                    if (isEmpty(rc, s, 4, placement)) ret ++;
165                } else if (d == (Constants.DAY_CODES[2] | Constants.DAY_CODES[4]) && isEmpty(rc, s, 2, placement) && isEmpty(rc, s, 4, placement)) {
166                    if (isEmpty(rc, s, 0, placement)) ret ++;
167                } else if (d == (Constants.DAY_CODES[0] | Constants.DAY_CODES[4]) && isEmpty(rc, s, 0, placement) && isEmpty(rc, s, 4, placement)) {
168                    if (isEmpty(rc, s, 2, placement)) ret ++;
169                }
170            }
171        }
172        if ((days & sDaysTTh) != 0 && (days & sDaysTTh) != sDaysTTh) {
173            for (int s = slot; s < slot + time.getLength(); s++) {
174                if (isEmpty(rc, s, 1, placement) && isEmpty(rc, s, 3, placement)) ret ++;
175                int d = (days & sDaysTTh);
176                if (d == Constants.DAY_CODES[1] && isEmpty(rc, s, 1, placement) && !isEmpty(rc, s, 3, placement)) ret --;
177                if (d == Constants.DAY_CODES[3] && isEmpty(rc, s, 3, placement) && !isEmpty(rc, s, 1, placement)) ret --;
178            }
179        }
180        return ret;
181    }
182    
183    /** Number of useless slots for this room */
184    public static int countUselessSlotsBrokenTimePatterns(RoomConstraint rc) {
185        int ret = 0;
186        for (int d = 0; d < Constants.NR_DAYS; d++) {
187            for (int s = 0; s < Constants.SLOTS_PER_DAY; s++) {
188                int slot = d * Constants.SLOTS_PER_DAY + s;
189                if (rc.getResource(slot).isEmpty()) {
190                    switch (d) {
191                        case 0:
192                            if (!rc.getResource(2 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getResource(4 * Constants.SLOTS_PER_DAY + s).isEmpty())
193                                ret++;
194                            break;
195                        case 1:
196                            if (!rc.getResource(3 * Constants.SLOTS_PER_DAY + s).isEmpty())
197                                ret++;
198                            break;
199                        case 2:
200                            if (!rc.getResource(0 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getResource(4 * Constants.SLOTS_PER_DAY + s).isEmpty())
201                                ret++;
202                            break;
203                        case 3:
204                            if (!rc.getResource(1 * Constants.SLOTS_PER_DAY + s).isEmpty())
205                                ret++;
206                            break;
207                        case 4:
208                            if (!rc.getResource(0 * Constants.SLOTS_PER_DAY + s).isEmpty() && !rc.getResource(2 * Constants.SLOTS_PER_DAY + s).isEmpty())
209                                ret++;
210                            break;
211                    }
212                }
213            }
214        }
215        return ret;
216    }
217}