001package org.cpsolver.coursett.constraint; 002 003import java.util.ArrayList; 004import java.util.BitSet; 005import java.util.HashSet; 006import java.util.HashMap; 007import java.util.Iterator; 008import java.util.List; 009import java.util.Set; 010 011import org.cpsolver.coursett.Constants; 012import org.cpsolver.coursett.criteria.DistributionPreferences; 013import org.cpsolver.coursett.model.Lecture; 014import org.cpsolver.coursett.model.Placement; 015import org.cpsolver.coursett.model.TimeLocation; 016import org.cpsolver.coursett.model.TimetableModel; 017import org.cpsolver.ifs.assignment.Assignment; 018import org.cpsolver.ifs.assignment.context.AssignmentConstraintContext; 019import org.cpsolver.ifs.assignment.context.ConstraintWithContext; 020import org.cpsolver.ifs.model.Constraint; 021import org.cpsolver.ifs.model.GlobalConstraint; 022import org.cpsolver.ifs.model.Model; 023import org.cpsolver.ifs.model.WeakeningConstraint; 024import org.cpsolver.ifs.util.DataProperties; 025import org.cpsolver.ifs.util.DistanceMetric; 026import org.cpsolver.ifs.util.ToolBox; 027 028 029/** 030 * Group constraint. <br> 031 * This constraint expresses relations between several classes, e.g., that two 032 * sections of the same lecture can not be taught at the same time, or that some 033 * classes have to be taught one immediately after another. It can be either 034 * hard or soft. <br> 035 * <br> 036 * Following constraints are now supported: 037 * <table border='1' summary='Related Solver Parameters'> 038 * <tr> 039 * <th>Constraint</th> 040 * <th>Comment</th> 041 * </tr> 042 * <tr> 043 * <td>SAME_TIME</td> 044 * <td>Same time: given classes have to be taught in the same hours. If the 045 * classes are of different length, the smaller one cannot start before the 046 * longer one and it cannot end after the longer one.</td> 047 * </tr> 048 * <tr> 049 * <td>SAME_DAYS</td> 050 * <td>Same days: given classes have to be taught in the same day. If the 051 * classes are of different time patterns, the days of one class have to form a 052 * subset of the days of the other class.</td> 053 * </tr> 054 * <tr> 055 * <td>BTB</td> 056 * <td>Back-to-back constraint: given classes have to be taught in the same room 057 * and they have to follow one strictly after another.</td> 058 * </tr> 059 * <tr> 060 * <td>BTB_TIME</td> 061 * <td>Back-to-back constraint: given classes have to follow one strictly after 062 * another, but they can be taught in different rooms.</td> 063 * </tr> 064 * <tr> 065 * <td>DIFF_TIME</td> 066 * <td>Different time: given classes cannot overlap in time.</td> 067 * </tr> 068 * <tr> 069 * <td>NHB(1), NHB(1.5), NHB(2), ... NHB(8)</td> 070 * <td>Number of hours between: between the given classes, the exact number of 071 * hours have to be kept.</td> 072 * </tr> 073 * <tr> 074 * <td>SAME_START</td> 075 * <td>Same starting hour: given classes have to start in the same hour.</td> 076 * </tr> 077 * <tr> 078 * <td>SAME_ROOM</td> 079 * <td>Same room: given classes have to be placed in the same room.</td> 080 * </tr> 081 * <tr> 082 * <td>NHB_GTE(1)</td> 083 * <td>Greater than or equal to 1 hour between: between the given classes, the 084 * number of hours have to be one or more.</td> 085 * </tr> 086 * <tr> 087 * <td>NHB_LT(6)</td> 088 * <td>Less than 6 hours between: between the given classes, the number of hours 089 * have to be less than six.</td> 090 * </tr> 091 * </table> 092 * 093 * @version CourseTT 1.3 (University Course Timetabling)<br> 094 * Copyright (C) 2006 - 2014 Tomas Muller<br> 095 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 096 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 097 * <br> 098 * This library is free software; you can redistribute it and/or modify 099 * it under the terms of the GNU Lesser General Public License as 100 * published by the Free Software Foundation; either version 3 of the 101 * License, or (at your option) any later version. <br> 102 * <br> 103 * This library is distributed in the hope that it will be useful, but 104 * WITHOUT ANY WARRANTY; without even the implied warranty of 105 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 106 * Lesser General Public License for more details. <br> 107 * <br> 108 * You should have received a copy of the GNU Lesser General Public 109 * License along with this library; if not see 110 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 111 */ 112 113public class GroupConstraint extends ConstraintWithContext<Lecture, Placement, GroupConstraint.GroupConstraintContext> { 114 private Long iConstraintId; 115 private int iPreference; 116 private ConstraintType iType; 117 private boolean iIsRequired; 118 private boolean iIsProhibited; 119 private int iDayOfWeekOffset = 0; 120 private boolean iPrecedenceConsiderDatePatterns = true; 121 private boolean iMaxNHoursADayConsiderDatePatterns = true; 122 private int iForwardCheckMaxDepth = 2; 123 private int iForwardCheckMaxDomainSize = 1000; 124 private int iNrWorkDays = 5; 125 126 /** 127 * Group constraints that can be checked on pairs of classes (e.g., same room means any two classes are in the same room), 128 * only need to implement this interface. 129 */ 130 public static interface PairCheck { 131 /** 132 * Check whether the constraint is satisfied for the given two assignments (required / preferred case) 133 * @param gc Calling group constraint 134 * @param plc1 First placement 135 * @param plc2 Second placement 136 * @return true if constraint is satisfied 137 */ 138 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2); 139 /** 140 * Check whether the constraint is satisfied for the given two assignments (prohibited / discouraged case) 141 * @param gc Calling group constraint 142 * @param plc1 First placement 143 * @param plc2 Second placement 144 * @return true if constraint is satisfied 145 */ 146 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2); 147 } 148 149 /** 150 * Group constraints that can be checked on pairs of classes (e.g., same room means any two classes are in the same room), 151 * only need to implement this interface. Unlike {@link PairCheck}, this check is also given current assignment. 152 */ 153 public static interface AssignmentPairCheck { 154 /** 155 * Check whether the constraint is satisfied for the given two assignments (required / preferred case) 156 * @param assignment current assignment 157 * @param gc Calling group constraint 158 * @param plc1 First placement 159 * @param plc2 Second placement 160 * @return true if constraint is satisfied 161 */ 162 public boolean isSatisfied(Assignment<Lecture, Placement> assignment, GroupConstraint gc, Placement plc1, Placement plc2); 163 /** 164 * Check whether the constraint is satisfied for the given two assignments (prohibited / discouraged case) 165 * @param assignment current assignment 166 * @param gc Calling group constraint 167 * @param plc1 First placement 168 * @param plc2 Second placement 169 * @return true if constraint is satisfied 170 */ 171 public boolean isViolated(Assignment<Lecture, Placement> assignment, GroupConstraint gc, Placement plc1, Placement plc2); 172 } 173 174 /** 175 * Group constraint building blocks (individual constraints that need more than {@link PairCheck}) 176 */ 177 public static enum Flag { 178 /** Back-to-back constraint (sequence check) */ 179 BACK_TO_BACK, 180 /** Can share room flag */ 181 CAN_SHARE_ROOM, 182 /** Maximum hours a day (number of slots a day check) */ 183 MAX_HRS_DAY, 184 /** Children cannot overlap */ 185 CH_NOTOVERLAP; 186 /** Bit number (to combine flags) */ 187 int flag() { return 1 << ordinal(); } 188 } 189 190 /** 191 * Group constraint type. 192 */ 193 public static enum ConstraintType { 194 /** 195 * Same Time: Given classes must be taught at the same time of day (independent of the actual day the classes meet). 196 * For the classes of the same length, this is the same constraint as same start. For classes of different length, 197 * the shorter one cannot start before, nor end after, the longer one.<BR> 198 * When prohibited or (strongly) discouraged: one class may not meet on any day at a time of day that overlaps with 199 * that of the other. For example, one class can not meet M 7:30 while the other meets F 7:30. Note the difference 200 * here from the different time constraint that only prohibits the actual class meetings from overlapping. 201 */ 202 SAME_TIME("SAME_TIME", "Same Time", new PairCheck() { 203 @Override 204 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 205 return sameHours(plc1.getTimeLocation().getStartSlot(), plc1.getTimeLocation().getLength(), 206 plc2.getTimeLocation().getStartSlot(), plc2.getTimeLocation().getLength()); 207 } 208 @Override 209 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 210 return !(plc1.getTimeLocation().shareHours(plc2.getTimeLocation())); 211 }}), 212 /** 213 * Same Days: Given classes must be taught on the same days. In case of classes of different time patterns, a class 214 * with fewer meetings must meet on a subset of the days used by the class with more meetings. For example, if one 215 * class pattern is 3x50, all others given in the constraint can only be taught on Monday, Wednesday, or Friday. 216 * For a 2x100 class MW, MF, WF is allowed but TTh is prohibited.<BR> 217 * When prohibited or (strongly) discouraged: any pair of classes classes cannot be taught on the same days (cannot 218 * overlap in days). For instance, if one class is MFW, the second has to be TTh. 219 */ 220 SAME_DAYS("SAME_DAYS", "Same Days", new PairCheck() { 221 @Override 222 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 223 return sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 224 } 225 @Override 226 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 227 return !plc1.getTimeLocation().shareDays(plc2.getTimeLocation()); 228 }}), 229 /** 230 * Back-To-Back & Same Room: Classes must be offered in adjacent time segments and must be placed in the same room. 231 * Given classes must also be taught on the same days.<BR> 232 * When prohibited or (strongly) discouraged: classes cannot be back-to-back. There must be at least half-hour 233 * between these classes, and they must be taught on the same days and in the same room. 234 */ 235 BTB("BTB", "Back-To-Back & Same Room", new PairCheck() { 236 @Override 237 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 238 return 239 plc1.sameRooms(plc2) && 240 sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 241 } 242 @Override 243 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 244 return 245 plc1.sameRooms(plc2) && 246 sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 247 }}, Flag.BACK_TO_BACK), 248 /** 249 * Back-To-Back: Classes must be offered in adjacent time segments but may be placed in different rooms. Given classes 250 * must also be taught on the same days.<BR> 251 * When prohibited or (strongly) discouraged: no pair of classes can be taught back-to-back. They may not overlap in time, 252 * but must be taught on the same days. This means that there must be at least half-hour between these classes. 253 */ 254 BTB_TIME("BTB_TIME", "Back-To-Back", new PairCheck() { 255 @Override 256 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 257 return sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 258 } 259 @Override 260 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 261 return sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 262 }}, Flag.BACK_TO_BACK), 263 /** 264 * Different Time: Given classes cannot overlap in time. They may be taught at the same time of day if they are on 265 * different days. For instance, MF 7:30 is compatible with TTh 7:30.<BR> 266 * When prohibited or (strongly) discouraged: every pair of classes in the constraint must overlap in time. 267 */ 268 DIFF_TIME("DIFF_TIME", "Different Time", new PairCheck() { 269 @Override 270 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 271 return !plc1.getTimeLocation().hasIntersection(plc2.getTimeLocation()); 272 } 273 @Override 274 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 275 return plc1.getTimeLocation().hasIntersection(plc2.getTimeLocation()); 276 }}), 277 /** 278 * 1 Hour Between: Given classes must have exactly 1 hour in between the end of one and the beginning of another. 279 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 280 * When prohibited or (strongly) discouraged: classes can not have 1 hour in between. They may not overlap in time 281 * but must be taught on the same days. 282 */ 283 NHB_1("NHB(1)", "1 Hour Between", 10, 12, BTB_TIME.check(), Flag.BACK_TO_BACK), 284 /** 285 * 2 Hours Between: Given classes must have exactly 2 hours in between the end of one and the beginning of another. 286 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 287 * When prohibited or (strongly) discouraged: classes can not have 2 hours in between. They may not overlap in time 288 * but must be taught on the same days. 289 */ 290 NHB_2("NHB(2)", "2 Hours Between", 20, 24, BTB_TIME.check(), Flag.BACK_TO_BACK), 291 /** 292 * 3 Hours Between: Given classes must have exactly 3 hours in between the end of one and the beginning of another. 293 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 294 * When prohibited or (strongly) discouraged: classes can not have 3 hours in between. They may not overlap in time 295 * but must be taught on the same days. 296 */ 297 NHB_3("NHB(3)", "3 Hours Between", 30, 36, BTB_TIME.check(), Flag.BACK_TO_BACK), 298 /** 299 * 4 Hours Between: Given classes must have exactly 4 hours in between the end of one and the beginning of another. 300 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 301 * When prohibited or (strongly) discouraged: classes can not have 4 hours in between. They may not overlap in time 302 * but must be taught on the same days. 303 */ 304 NHB_4("NHB(4)", "4 Hours Between", 40, 48, BTB_TIME.check(), Flag.BACK_TO_BACK), 305 /** 306 * 5 Hours Between: Given classes must have exactly 5 hours in between the end of one and the beginning of another. 307 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 308 * When prohibited or (strongly) discouraged: classes can not have 5 hours in between. They may not overlap in time 309 * but must be taught on the same days. 310 */ 311 NHB_5("NHB(5)", "5 Hours Between", 50, 60, BTB_TIME.check(), Flag.BACK_TO_BACK), 312 /** 313 * 6 Hours Between: Given classes must have exactly 6 hours in between the end of one and the beginning of another. 314 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 315 * When prohibited or (strongly) discouraged: classes can not have 6 hours in between. They may not overlap in time 316 * but must be taught on the same days. 317 */ 318 NHB_6("NHB(6)", "6 Hours Between", 60, 72, BTB_TIME.check(), Flag.BACK_TO_BACK), 319 /** 320 * 7 Hours Between: Given classes must have exactly 7 hours in between the end of one and the beginning of another. 321 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 322 * When prohibited or (strongly) discouraged: classes can not have 7 hours in between. They may not overlap in time 323 * but must be taught on the same days. 324 */ 325 NHB_7("NHB(7)", "7 Hours Between", 70, 84, BTB_TIME.check(), Flag.BACK_TO_BACK), 326 /** 327 * 8 Hours Between: Given classes must have exactly 8 hours in between the end of one and the beginning of another. 328 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 329 * When prohibited or (strongly) discouraged: classes can not have 8 hours in between. They may not overlap in time 330 * but must be taught on the same days. 331 */ 332 NHB_8("NHB(8)", "8 Hours Between", 80, 96, BTB_TIME.check(), Flag.BACK_TO_BACK), 333 /** 334 * Same Start Time: Given classes must start during the same half-hour period of a day (independent of the actual 335 * day the classes meet). For instance, MW 7:30 is compatible with TTh 7:30 but not with MWF 8:00.<BR> 336 * When prohibited or (strongly) discouraged: any pair of classes in the given constraint cannot start during the 337 * same half-hour period of any day of the week. 338 */ 339 SAME_START("SAME_START", "Same Start Time", new PairCheck() { 340 @Override 341 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 342 return 343 (plc1.getTimeLocation().getStartSlot() % Constants.SLOTS_PER_DAY) == 344 (plc2.getTimeLocation().getStartSlot() % Constants.SLOTS_PER_DAY); 345 } 346 @Override 347 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 348 return 349 (plc1.getTimeLocation().getStartSlot() % Constants.SLOTS_PER_DAY) != 350 (plc2.getTimeLocation().getStartSlot() % Constants.SLOTS_PER_DAY); 351 }}), 352 /** 353 * Same Room: Given classes must be taught in the same room.<BR> 354 * When prohibited or (strongly) discouraged: any pair of classes in the constraint cannot be taught in the same room. 355 */ 356 SAME_ROOM("SAME_ROOM", "Same Room", new PairCheck() { 357 @Override 358 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 359 return plc1.sameRooms(plc2); 360 } 361 @Override 362 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 363 return !plc1.sameRooms(plc2); 364 }}), 365 /** 366 * At Least 1 Hour Between: Given classes have to have 1 hour or more in between.<BR> 367 * When prohibited or (strongly) discouraged: given classes have to have less than 1 hour in between. 368 */ 369 NHB_GTE_1("NHB_GTE(1)", "At Least 1 Hour Between", 6, 288, BTB_TIME.check(), Flag.BACK_TO_BACK), 370 /** 371 * Less Than 6 Hours Between: Given classes must have less than 6 hours from end of first class to the beginning of 372 * the next. Given classes must also be taught on the same days.<BR> 373 * When prohibited or (strongly) discouraged: given classes must have 6 or more hours between. This constraint does 374 * not carry over from classes taught at the end of one day to the beginning of the next. 375 */ 376 NHB_LT_6("NHB_LT(6)", "Less Than 6 Hours Between", 0, 72, BTB_TIME.check(), Flag.BACK_TO_BACK), 377 /** 378 * 1.5 Hour Between: Given classes must have exactly 90 minutes in between the end of one and the beginning of another. 379 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 380 * When prohibited or (strongly) discouraged: classes can not have 90 minutes in between. They may not overlap in time 381 * but must be taught on the same days. 382 */ 383 NHB_1_5("NHB(1.5)", "1.5 Hour Between", 15, 18, BTB_TIME.check(), Flag.BACK_TO_BACK), 384 /** 385 * 4.5 Hours Between: Given classes must have exactly 4.5 hours in between the end of one and the beginning of another. 386 * As with the <i>back-to-back time</i> constraint, given classes must be taught on the same days.<BR> 387 * When prohibited or (strongly) discouraged: classes can not have 4.5 hours in between. They may not overlap in time 388 * but must be taught on the same days. 389 */ 390 NHB_4_5("NHB(4.5)", "4.5 Hours Between", 45, 54, BTB_TIME.check(), Flag.BACK_TO_BACK), 391 /** 392 * Same Students: Given classes are treated as they are attended by the same students, i.e., they cannot overlap in time 393 * and if they are back-to-back the assigned rooms cannot be too far (student limit is used). 394 */ 395 SAME_STUDENTS("SAME_STUDENTS", "Same Students", new PairCheck() { 396 @Override 397 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 398 return !JenrlConstraint.isInConflict(plc1, plc2, ((TimetableModel)gc.getModel()).getDistanceMetric()); 399 } 400 @Override 401 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 402 return true; 403 }}), 404 /** 405 * Same Instructor: Given classes are treated as they are taught by the same instructor, i.e., they cannot overlap in time 406 * and if they are back-to-back the assigned rooms cannot be too far (instructor limit is used).<BR> 407 * If the constraint is required and the classes are back-to-back, discouraged and strongly discouraged distances between 408 * assigned rooms are also considered. 409 */ 410 SAME_INSTR("SAME_INSTR", "Same Instructor", new PairCheck() { 411 @Override 412 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 413 TimeLocation t1 = plc1.getTimeLocation(), t2 = plc2.getTimeLocation(); 414 if (t1.shareDays(t2) && t1.shareWeeks(t2)) { 415 if (t1.shareHours(t2)) return false; // overlap 416 DistanceMetric m = ((TimetableModel)gc.getModel()).getDistanceMetric(); 417 if ((t1.getStartSlot() + t1.getLength() == t2.getStartSlot() || t2.getStartSlot() + t2.getLength() == t1.getStartSlot())) { 418 if (Placement.getDistanceInMeters(m, plc1, plc2) > m.getInstructorProhibitedLimit()) 419 return false; 420 } else if (m.doComputeDistanceConflictsBetweenNonBTBClasses()) { 421 if (t1.getStartSlot() + t1.getLength() < t2.getStartSlot() && 422 Placement.getDistanceInMinutes(m, plc1, plc2) > t1.getBreakTime() + Constants.SLOT_LENGTH_MIN * (t2.getStartSlot() - t1.getStartSlot() - t1.getLength())) 423 return false; 424 if (t2.getStartSlot() + t2.getLength() < t1.getStartSlot() && 425 Placement.getDistanceInMinutes(m, plc1, plc2) > t2.getBreakTime() + Constants.SLOT_LENGTH_MIN * (t1.getStartSlot() - t2.getStartSlot() - t2.getLength())) 426 return false; 427 } 428 } 429 return true; 430 } 431 @Override 432 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 433 return true; 434 }}), 435 /** 436 * Can Share Room: Given classes can share the room (use the room in the same time) if the room is big enough. 437 */ 438 CAN_SHARE_ROOM("CAN_SHARE_ROOM", "Can Share Room", Flag.CAN_SHARE_ROOM), 439 /** 440 * Precedence: Given classes have to be taught in the given order (the first meeting of the first class has to end before 441 * the first meeting of the second class etc.)<BR> 442 * When prohibited or (strongly) discouraged: classes have to be taught in the order reverse to the given one. 443 */ 444 PRECEDENCE("PRECEDENCE", "Precedence", new PairCheck() { 445 @Override 446 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 447 return gc.isPrecedence(plc1, plc2, true, true); 448 } 449 @Override 450 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 451 return gc.isPrecedence(plc1, plc2, false, true); 452 }}), 453 /** 454 * Back-To-Back Day: Classes must be offered on adjacent days and may be placed in different rooms.<BR> 455 * When prohibited or (strongly) discouraged: classes can not be taught on adjacent days. They also can not be taught 456 * on the same days. This means that there must be at least one day between these classes. 457 */ 458 BTB_DAY("BTB_DAY", "Back-To-Back Day", new PairCheck() { 459 @Override 460 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 461 return 462 !sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()) && 463 isBackToBackDays(plc1.getTimeLocation(), plc2.getTimeLocation()); 464 } 465 @Override 466 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 467 return 468 !sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()) && 469 !isBackToBackDays(plc1.getTimeLocation(), plc2.getTimeLocation()); 470 }}), 471 /** 472 * Meet Together: Given classes are meeting together (same as if the given classes require constraints Can Share Room, 473 * Same Room, Same Time and Same Days all together). 474 */ 475 MEET_WITH("MEET_WITH", "Meet Together", new PairCheck() { 476 @Override 477 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 478 return 479 plc1.sameRooms(plc2) && 480 sameHours(plc1.getTimeLocation().getStartSlot(), plc1.getTimeLocation().getLength(), 481 plc2.getTimeLocation().getStartSlot(), plc2.getTimeLocation().getLength()) && 482 sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 483 484 } 485 @Override 486 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 487 return true; 488 }}, Flag.CAN_SHARE_ROOM), 489 /** 490 * More Than 1 Day Between: Given classes must have two or more days in between.<br> 491 * When prohibited or (strongly) discouraged: given classes must be offered on adjacent days or with at most one day in between. 492 */ 493 NDB_GT_1("NDB_GT_1", "More Than 1 Day Between", new PairCheck() { 494 @Override 495 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 496 return 497 !sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()) && 498 isNrDaysBetweenGreaterThanOne(plc1.getTimeLocation(), plc2.getTimeLocation()); 499 } 500 @Override 501 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 502 return 503 !sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()) && 504 !isNrDaysBetweenGreaterThanOne(plc1.getTimeLocation(), plc2.getTimeLocation()); 505 }}), 506 /** 507 * Children Cannot Overlap: If parent classes do not overlap in time, children classes can not overlap in time as well.<BR> 508 * Note: This constraint only needs to be put on the parent classes. Preferred configurations are Required All Classes 509 * or Pairwise (Strongly) Preferred. 510 */ 511 CH_NOTOVERLAP("CH_NOTOVERLAP", "Children Cannot Overlap", new AssignmentPairCheck() { 512 @Override 513 public boolean isSatisfied(Assignment<Lecture, Placement> assignment, GroupConstraint gc, Placement plc1, Placement plc2) { 514 return gc.isChildrenNotOverlap(assignment, plc1.variable(), plc1, plc2.variable(), plc2); 515 } 516 @Override 517 public boolean isViolated(Assignment<Lecture, Placement> assignment, GroupConstraint gc, Placement plc1, Placement plc2) { 518 return true; 519 }}), 520 /** 521 * Next Day: The second class has to be placed on the following day of the first class (if the first class is on Friday, 522 * second class have to be on Monday).<br> 523 * When prohibited or (strongly) discouraged: The second class has to be placed on the previous day of the first class 524 * (if the first class is on Monday, second class have to be on Friday).<br> 525 * Note: This constraint works only between pairs of classes. 526 */ 527 FOLLOWING_DAY("FOLLOWING_DAY", "Next Day", new PairCheck() { 528 @Override 529 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 530 return gc.isFollowingDay(plc1, plc2, true); 531 } 532 @Override 533 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 534 return gc.isFollowingDay(plc1, plc2, false); 535 }}), 536 /** 537 * Two Days After: The second class has to be placed two days after the first class (Monday → Wednesday, Tuesday → 538 * Thurday, Wednesday → Friday, Thursday → Monday, Friday → Tuesday).<br> 539 * When prohibited or (strongly) discouraged: The second class has to be placed two days before the first class (Monday → 540 * Thursday, Tuesday → Friday, Wednesday → Monday, Thursday → Tuesday, Friday → Wednesday).<br> 541 * Note: This constraint works only between pairs of classes. 542 */ 543 EVERY_OTHER_DAY("EVERY_OTHER_DAY", "Two Days After", new PairCheck() { 544 @Override 545 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 546 return gc.isEveryOtherDay(plc1, plc2, true); 547 } 548 @Override 549 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 550 return gc.isEveryOtherDay(plc1, plc2, false); 551 }}), 552 /** 553 * At Most 3 Hours A Day: Classes are to be placed in a way that there is no more than three hours in any day. 554 */ 555 MAX_HRS_DAY_3("MAX_HRS_DAY(3)", "At Most 3 Hours A Day", 36, null, Flag.MAX_HRS_DAY), 556 /** 557 * At Most 4 Hours A Day: Classes are to be placed in a way that there is no more than four hours in any day. 558 */ 559 MAX_HRS_DAY_4("MAX_HRS_DAY(4)", "At Most 4 Hours A Day", 48, null, Flag.MAX_HRS_DAY), 560 /** 561 * At Most 5 Hours A Day: Classes are to be placed in a way that there is no more than five hours in any day. 562 */ 563 MAX_HRS_DAY_5("MAX_HRS_DAY(5)", "At Most 5 Hours A Day", 60, null, Flag.MAX_HRS_DAY), 564 /** 565 * At Most 6 Hours A Day: Classes are to be placed in a way that there is no more than six hours in any day. 566 */ 567 MAX_HRS_DAY_6("MAX_HRS_DAY(6)", "At Most 6 Hours A Day", 72, null, Flag.MAX_HRS_DAY), 568 /** 569 * At Most 7 Hours A Day: Classes are to be placed in a way that there is no more than seven hours in any day. 570 */ 571 MAX_HRS_DAY_7("MAX_HRS_DAY(7)", "At Most 7 Hours A Day", 84, null, Flag.MAX_HRS_DAY), 572 /** 573 * At Most 8 Hours A Day: Classes are to be placed in a way that there is no more than eight hours in any day. 574 */ 575 MAX_HRS_DAY_8("MAX_HRS_DAY(8)", "At Most 8 Hours A Day", 96, null, Flag.MAX_HRS_DAY), 576 /** 577 * At Most 9 Hours A Day: Classes are to be placed in a way that there is no more than nine hours in any day. 578 */ 579 MAX_HRS_DAY_9("MAX_HRS_DAY(9)", "At Most 9 Hours A Day", 108, null, Flag.MAX_HRS_DAY), 580 /** 581 * At Most 10 Hours A Day: Classes are to be placed in a way that there is no more than ten hours in any day. 582 */ 583 MAX_HRS_DAY_10("MAX_HRS_DAY(10)", "At Most 10 Hours A Day", 120, null, Flag.MAX_HRS_DAY), 584 /** 585 * Given classes must be taught during the same weeks (i.e., must have the same date pattern).<br> 586 * When prohibited or (strongly) discouraged: any two classes must have non overlapping date patterns. 587 */ 588 SAME_WEEKS("SAME_WEEKS", "Same Weeks", new PairCheck() { 589 @Override 590 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 591 return plc1.getTimeLocation().getWeekCode().equals(plc2.getTimeLocation().getWeekCode()); 592 } 593 @Override 594 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 595 return !plc1.getTimeLocation().shareWeeks(plc2.getTimeLocation()); 596 }}), 597 /** 598 * Classes (of different courses) are to be attended by the same students. For instance, 599 * if class A1 (of a course A) and class B1 (of a course B) are linked, a student requesting 600 * both courses must attend A1 if and only if he also attends B1. This is a student sectioning 601 * constraint that is interpreted as Same Students constraint during course timetabling. 602 */ 603 LINKED_SECTIONS("LINKED_SECTIONS", "Linked Classes", SAME_STUDENTS.check()), 604 /** 605 * Back-To-Back Precedence: Given classes have to be taught in the given order, on the same days, 606 * and in adjacent time segments. 607 * When prohibited or (strongly) discouraged: Given classes have to be taught in the given order, 608 * on the same days, but cannot be back-to-back. 609 */ 610 BTB_PRECEDENCE("BTB_PRECEDENCE", "Back-To-Back Precedence", new PairCheck() { 611 @Override 612 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 613 return gc.isPrecedence(plc1, plc2, true, false) && sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 614 } 615 @Override 616 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 617 return gc.isPrecedence(plc1, plc2, true, false) && sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 618 }}, Flag.BACK_TO_BACK), 619 620 /** 621 * Same Days-Time: Given classes must be taught at the same time of day and on the same days. 622 * It is the combination of Same Days and Same Time distribution preferences. 623 * When prohibited or (strongly) discouraged: Any pair of classes classes cannot be taught on the same days 624 * during the same time. 625 */ 626 SAME_DAYS_TIME("SAME_D_T", "Same Days-Time", new PairCheck() { 627 @Override 628 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 629 return sameHours(plc1.getTimeLocation().getStartSlot(), plc1.getTimeLocation().getLength(), 630 plc2.getTimeLocation().getStartSlot(), plc2.getTimeLocation().getLength()) && 631 sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()); 632 } 633 @Override 634 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 635 return !plc1.getTimeLocation().shareHours(plc2.getTimeLocation()) || 636 !plc1.getTimeLocation().shareDays(plc2.getTimeLocation()); 637 }}), 638 /** 639 * Same Days-Room-Time: Given classes must be taught at the same time of day, on the same days and in the same room. 640 * It is the combination of Same Days, Same Time and Same Room distribution preferences. 641 * Note that this constraint is the same as Meet Together constraint, except it does not allow room sharing. In other words, 642 * it is only useful when these classes are taught during non-overlapping date patterns. 643 * When prohibited or (strongly) discouraged: Any pair of classes classes cannot be taught on the same days 644 * during the same time in the same room. 645 */ 646 SAME_DAYS_ROOM_TIME("SAME_D_R_T", "Same Days-Room-Time", new PairCheck() { 647 @Override 648 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 649 return sameHours(plc1.getTimeLocation().getStartSlot(), plc1.getTimeLocation().getLength(), 650 plc2.getTimeLocation().getStartSlot(), plc2.getTimeLocation().getLength()) && 651 sameDays(plc1.getTimeLocation().getDaysArray(), plc2.getTimeLocation().getDaysArray()) && 652 plc1.sameRooms(plc2); 653 } 654 @Override 655 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { 656 return !plc1.getTimeLocation().shareHours(plc2.getTimeLocation()) || 657 !plc1.getTimeLocation().shareDays(plc2.getTimeLocation()) || 658 !plc1.sameRooms(plc2); 659 }}), 660 /** 661 * 6 Hour Work Day: Classes are to be placed in a way that there is no more than six hours between the start of the first class and the end of the class one on any day. 662 */ 663 WORKDAY_6("WORKDAY(6)", "6 Hour Work Day", 72, new PairCheck() { 664 @Override 665 public boolean isSatisfied(GroupConstraint gc, Placement plc1, Placement plc2) { 666 TimeLocation t1 = plc1.getTimeLocation(), t2 = plc2.getTimeLocation(); 667 if (t1 == null || t2 == null || !t1.shareDays(t2) || !t1.shareWeeks(t2)) return true; 668 return Math.max(t1.getStartSlot() + t1.getLength(), t2.getStartSlot() + t2.getLength()) - Math.min(t1.getStartSlot(), t2.getStartSlot()) <= gc.getType().getMax(); 669 } 670 @Override 671 public boolean isViolated(GroupConstraint gc, Placement plc1, Placement plc2) { return true; } 672 }), 673 /** 674 * 7 Hour Work Day: Classes are to be placed in a way that there is no more than seven hours between the start of the first class and the end of the class one on any day. 675 */ 676 WORKDAY_7("WORKDAY(7)", "7 Hour Work Day", 84, WORKDAY_6.check()), 677 /** 678 * 8 Hour Work Day: Classes are to be placed in a way that there is no more than eight hours between the start of the first class and the end of the class one on any day. 679 */ 680 WORKDAY_8("WORKDAY(8)", "8 Hour Work Day", 96, WORKDAY_6.check()), 681 /** 682 * 9 Hour Work Day: Classes are to be placed in a way that there is no more than nine hours between the start of the first class and the end of the class one on any day. 683 */ 684 WORKDAY_9("WORKDAY(9)", "9 Hour Work Day", 108, WORKDAY_6.check()), 685 /** 686 * 10 Hour Work Day: Classes are to be placed in a way that there is no more than ten hours between the start of the first class and the end of the class one on any day. 687 */ 688 WORKDAY_10("WORKDAY(10)", "10 Hour Work Day", 120, WORKDAY_6.check()), 689 /** 690 * 11 Hour Work Day: Classes are to be placed in a way that there is no more than eleven hours between the start of the first class and the end of the class one on any day. 691 */ 692 WORKDAY_11("WORKDAY(11)", "11 Hour Work Day", 132, WORKDAY_6.check()), 693 /** 694 * 12 Hour Work Day: Classes are to be placed in a way that there is no more than twelve hours between the start of the first class and the end of the class one on any day. 695 */ 696 WORKDAY_12("WORKDAY(12)", "12 Hour Work Day", 144, WORKDAY_6.check()), 697 ; 698 699 String iReference, iName; 700 int iFlag = 0; 701 Flag[] iFlags = null; 702 int iMin = 0, iMax = 0; 703 PairCheck iCheck = null; 704 AssignmentPairCheck iAssignmentCheck = null; 705 ConstraintType(String reference, String name, Flag... flags) { 706 iReference = reference; 707 iName = name; 708 iFlags = flags; 709 for (Flag f: flags) 710 iFlag |= f.flag(); 711 } 712 ConstraintType(String reference, String name, PairCheck check, Flag... flags) { 713 this(reference, name, flags); 714 iCheck = check; 715 } 716 ConstraintType(String reference, String name, AssignmentPairCheck check, Flag... flags) { 717 this(reference, name, flags); 718 iAssignmentCheck = check; 719 } 720 ConstraintType(String reference, String name, int limit, PairCheck check, Flag... flags) { 721 this(reference, name, check, flags); 722 iMin = iMax = limit; 723 } 724 ConstraintType(String reference, String name, int min, int max, PairCheck check, Flag... flags) { 725 this(reference, name, check, flags); 726 iMin = min; 727 iMax = max; 728 } 729 730 /** Constraint reference 731 * @return constraint reference 732 **/ 733 public String reference() { return iReference; } 734 /** Constraint name 735 * @return constraint name 736 **/ 737 public String getName() { return iName; } 738 /** Minimum (gap) parameter 739 * @return minimum gap (first constraint parameter) 740 **/ 741 public int getMin() { return iMin; } 742 /** Maximum (gap, hours a day) parameter 743 * @return maximum gap (second constraint parameter) 744 **/ 745 public int getMax() { return iMax; } 746 747 /** Flag check (true if contains given flag) 748 * @param f a flag to check 749 * @return true if present 750 **/ 751 public boolean is(Flag f) { return (iFlag & f.flag()) != 0; } 752 753 /** Constraint type from reference 754 * @param reference constraint reference 755 * @return constraint of the reference 756 **/ 757 public static ConstraintType get(String reference) { 758 for (ConstraintType t: ConstraintType.values()) 759 if (t.reference().equals(reference)) return t; 760 return null; 761 } 762 763 /** True if a required or preferred constraint is satisfied between a pair of placements 764 * @param assignment current assignment 765 * @param gc current constraint 766 * @param plc1 first placement 767 * @param plc2 second placement 768 * @return true if the two placements are consistent with the constraint if preferred or required 769 **/ 770 public boolean isSatisfied(Assignment<Lecture, Placement> assignment, GroupConstraint gc, Placement plc1, Placement plc2) { 771 if (iCheck != null && !iCheck.isSatisfied(gc, plc1, plc2)) 772 return false; 773 if (iAssignmentCheck != null && assignment != null && !iAssignmentCheck.isSatisfied(assignment, gc, plc1, plc2)) 774 return false; 775 return true; 776 } 777 /** True if a prohibited or discouraged constraint is satisfied between a pair of placements 778 * @param assignment current assignment 779 * @param gc current constraint 780 * @param plc1 first placement 781 * @param plc2 second placement 782 * @return true if the two placements are consistent with the constraint if discouraged or prohibited 783 **/ 784 public boolean isViolated(Assignment<Lecture, Placement> assignment, GroupConstraint gc, Placement plc1, Placement plc2) { 785 if (iCheck != null && !iCheck.isViolated(gc, plc1, plc2)) 786 return false; 787 if (iAssignmentCheck != null && assignment != null && !iAssignmentCheck.isViolated(assignment, gc, plc1, plc2)) 788 return false; 789 return true; 790 } 791 /** Pair check */ 792 private PairCheck check() { return iCheck; } 793 } 794 795 public GroupConstraint() { 796 } 797 798 @Override 799 public void setModel(Model<Lecture, Placement> model) { 800 super.setModel(model); 801 if (model != null) { 802 DataProperties config = ((TimetableModel)model).getProperties(); 803 iDayOfWeekOffset = config.getPropertyInt("DatePattern.DayOfWeekOffset", 0); 804 iPrecedenceConsiderDatePatterns = config.getPropertyBoolean("Precedence.ConsiderDatePatterns", true); 805 iForwardCheckMaxDepth = config.getPropertyInt("ForwardCheck.MaxDepth", iForwardCheckMaxDepth); 806 iForwardCheckMaxDomainSize = config.getPropertyInt("ForwardCheck.MaxDomainSize", iForwardCheckMaxDomainSize); 807 iMaxNHoursADayConsiderDatePatterns = config.getPropertyBoolean("MaxNHoursADay.ConsiderDatePatterns", iMaxNHoursADayConsiderDatePatterns); 808 iNrWorkDays = (config.getPropertyInt("General.LastWorkDay", 4) - config.getPropertyInt("General.FirstWorkDay", 0) + 1); 809 } 810 } 811 812 @Override 813 public void addVariable(Lecture lecture) { 814 if (!variables().contains(lecture)) 815 super.addVariable(lecture); 816 if (getType().is(Flag.CH_NOTOVERLAP)) { 817 if (lecture.getChildrenSubpartIds() != null) { 818 for (Long subpartId: lecture.getChildrenSubpartIds()) { 819 for (Lecture ch : lecture.getChildren(subpartId)) { 820 if (!variables().contains(ch)) 821 super.addVariable(ch); 822 } 823 } 824 } 825 } 826 } 827 828 @Override 829 public void removeVariable(Lecture lecture) { 830 if (variables().contains(lecture)) 831 super.removeVariable(lecture); 832 if (getType().is(Flag.CH_NOTOVERLAP)) { 833 if (lecture.getChildrenSubpartIds() != null) { 834 for (Long subpartId: lecture.getChildrenSubpartIds()) { 835 for (Lecture ch : lecture.getChildren(subpartId)) { 836 if (variables().contains(ch)) 837 super.removeVariable(ch); 838 } 839 } 840 } 841 } 842 } 843 844 /** 845 * Constructor 846 * 847 * @param id 848 * constraint id 849 * @param type 850 * constraString type (e.g, {@link ConstraintType#SAME_TIME}) 851 * @param preference 852 * time preference ("R" for required, "P" for prohibited, "-2", 853 * "-1", "1", "2" for soft preference) 854 */ 855 public GroupConstraint(Long id, ConstraintType type, String preference) { 856 iConstraintId = id; 857 iType = type; 858 iIsRequired = preference.equals(Constants.sPreferenceRequired); 859 iIsProhibited = preference.equals(Constants.sPreferenceProhibited); 860 iPreference = Constants.preference2preferenceLevel(preference); 861 } 862 863 /** Constraint id 864 * @return constraint unique id 865 **/ 866 public Long getConstraintId() { 867 return iConstraintId; 868 } 869 870 @Override 871 public long getId() { 872 return (iConstraintId == null ? -1 : iConstraintId.longValue()); 873 } 874 875 /** Generated unique id 876 * @return generated unique id 877 **/ 878 protected long getGeneratedId() { 879 return iId; 880 } 881 882 /** Return constraint type (e.g, {@link ConstraintType#SAME_TIME}) 883 * @return constraint type 884 **/ 885 public ConstraintType getType() { 886 return iType; 887 } 888 889 /** 890 * Set constraint type 891 * @param type constraint type 892 */ 893 public void setType(ConstraintType type) { 894 iType = type; 895 } 896 897 /** Is constraint required 898 * @return true if required 899 **/ 900 public boolean isRequired() { 901 return iIsRequired; 902 } 903 904 /** Is constraint prohibited 905 * @return true if prohibited 906 **/ 907 public boolean isProhibited() { 908 return iIsProhibited; 909 } 910 911 /** 912 * Prolog reference: "R" for required, "P" for prohibited", "-2",.."2" for 913 * preference 914 * @return prolog preference 915 */ 916 public String getPrologPreference() { 917 return Constants.preferenceLevel2preference(iPreference); 918 } 919 920 @Override 921 public boolean isConsistent(Placement value1, Placement value2) { 922 if (!isHard()) 923 return true; 924 if (!isSatisfiedPair(null, value1, value2)) 925 return false; 926 if (getType().is(Flag.BACK_TO_BACK)) { 927 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 928 assignments.put(value1.variable(), value1); 929 assignments.put(value2.variable(), value2); 930 if (!isSatisfiedSeq(null, assignments, null)) 931 return false; 932 } 933 if (getType().is(Flag.MAX_HRS_DAY)) { 934 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 935 assignments.put(value1.variable(), value1); 936 assignments.put(value2.variable(), value2); 937 for (int dayCode: Constants.DAY_CODES) { 938 if (iMaxNHoursADayConsiderDatePatterns) { 939 for (BitSet week: ((TimetableModel)getModel()).getWeeks()) { 940 if (!value1.getTimeLocation().shareWeeks(week) && !value2.getTimeLocation().shareWeeks(week)) continue; 941 if (nrSlotsADay(null, dayCode, week, assignments, null) > getType().getMax()) return false; 942 } 943 } else { 944 if (nrSlotsADay(null, dayCode, null, assignments, null) > getType().getMax()) return false; 945 } 946 } 947 } 948 return true; 949 } 950 951 @Override 952 public void computeConflicts(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) { 953 computeConflicts(assignment, value, conflicts, true); 954 } 955 956 public void computeConflictsNoForwardCheck(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) { 957 computeConflicts(assignment, value, conflicts, false); 958 } 959 960 public void computeConflicts(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts, boolean fwdCheck) { 961 if (!isHard()) 962 return; 963 for (Lecture v : variables()) { 964 if (v.equals(value.variable())) 965 continue; // ignore this variable 966 Placement p = assignment.getValue(v); 967 if (p == null) 968 continue; // there is an unassigned variable -- great, still a chance to get violated 969 if (!isSatisfiedPair(assignment, p, value)) 970 conflicts.add(p); 971 } 972 if (getType().is(Flag.BACK_TO_BACK)) { 973 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 974 assignments.put(value.variable(), value); 975 if (!isSatisfiedSeq(assignment, assignments, conflicts)) 976 conflicts.add(value); 977 } 978 if (getType().is(Flag.MAX_HRS_DAY)) { 979 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 980 assignments.put(value.variable(), value); 981 for (int dayCode: Constants.DAY_CODES) { 982 if (iMaxNHoursADayConsiderDatePatterns) { 983 for (BitSet week: ((TimetableModel)getModel()).getWeeks()) { 984 if (!value.getTimeLocation().shareWeeks(week)) continue; 985 if (nrSlotsADay(assignment, dayCode, week, assignments, conflicts) > getType().getMax()) { 986 List<Placement> adepts = new ArrayList<Placement>(); 987 for (Lecture l: variables()) { 988 if (l.equals(value.variable())) continue; 989 Placement p = assignment.getValue(l); 990 if (p == null || conflicts.contains(p) || p.getTimeLocation() == null) continue; 991 if ((p.getTimeLocation().getDayCode() & dayCode) == 0 || !p.getTimeLocation().shareWeeks(week)) continue; 992 adepts.add(p); 993 } 994 do { 995 Placement conflict = ToolBox.random(adepts); 996 adepts.remove(conflict); 997 conflicts.add(conflict); 998 } while (!adepts.isEmpty() && nrSlotsADay(assignment, dayCode, week, assignments, conflicts) > getType().getMax()); 999 } 1000 } 1001 } else { 1002 if (nrSlotsADay(assignment, dayCode, null, assignments, conflicts) > getType().getMax()) { 1003 List<Placement> adepts = new ArrayList<Placement>(); 1004 for (Lecture l: variables()) { 1005 if (l.equals(value.variable())) continue; 1006 Placement p = assignment.getValue(l); 1007 if (p == null || conflicts.contains(p) || p.getTimeLocation() == null) continue; 1008 if ((p.getTimeLocation().getDayCode() & dayCode) == 0) continue; 1009 adepts.add(p); 1010 } 1011 do { 1012 Placement conflict = ToolBox.random(adepts); 1013 adepts.remove(conflict); 1014 conflicts.add(conflict); 1015 } while (!adepts.isEmpty() && nrSlotsADay(assignment, dayCode, null, assignments, conflicts) > getType().getMax()); 1016 } 1017 } 1018 } 1019 } 1020 1021 // Forward checking 1022 if (fwdCheck) forwardCheck(assignment, value, conflicts, new HashSet<GroupConstraint>(), iForwardCheckMaxDepth - 1); 1023 } 1024 1025 public void forwardCheck(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts, Set<GroupConstraint> ignore, int depth) { 1026 try { 1027 if (depth < 0) return; 1028 ignore.add(this); 1029 1030 int neededSize = value.variable().maxRoomUse(); 1031 1032 for (Lecture lecture: variables()) { 1033 if (conflicts.contains(value)) break; // already conflicting 1034 1035 if (lecture.equals(value.variable())) continue; // Skip this lecture 1036 Placement current = assignment.getValue(lecture); 1037 if (current != null) { // Has assignment, check whether it is conflicting 1038 if (isSatisfiedPair(assignment, value, current)) { 1039 // Increase needed size if the assignment is of the same room and overlapping in time 1040 if (canShareRoom() && sameRoomAndOverlaps(value, current)) { 1041 neededSize += lecture.maxRoomUse(); 1042 } 1043 continue; 1044 } 1045 conflicts.add(current); 1046 } 1047 1048 // Look for supporting assignments assignment 1049 boolean shareRoomAndOverlaps = canShareRoom(); 1050 Placement support = null; 1051 int nrSupports = 0; 1052 if (lecture.nrValues() >= iForwardCheckMaxDomainSize) { 1053 // ignore variables with large domains 1054 return; 1055 } 1056 List<Placement> values = lecture.values(assignment); 1057 if (values.isEmpty()) { 1058 // ignore variables with empty domain 1059 return; 1060 } 1061 for (Placement other: values) { 1062 if (nrSupports < 2) { 1063 if (isSatisfiedPair(assignment, value, other)) { 1064 if (support == null) support = other; 1065 nrSupports ++; 1066 if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other)) 1067 shareRoomAndOverlaps = false; 1068 } 1069 } else if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other) && isSatisfiedPair(assignment, value, other)) { 1070 shareRoomAndOverlaps = false; 1071 } 1072 if (nrSupports > 1 && !shareRoomAndOverlaps) 1073 break; 1074 } 1075 1076 // No supporting assignment -> fail 1077 if (nrSupports == 0) { 1078 conflicts.add(value); // other class cannot be assigned with this value 1079 return; 1080 } 1081 // Increase needed size if all supporters are of the same room and in overlapping times 1082 if (shareRoomAndOverlaps) { 1083 neededSize += lecture.maxRoomUse(); 1084 } 1085 1086 // Only one supporter -> propagate the new assignment over other hard constraints of the lecture 1087 if (nrSupports == 1) { 1088 for (Constraint<Lecture, Placement> other: lecture.hardConstraints()) { 1089 if (other instanceof WeakeningConstraint) continue; 1090 if (other instanceof GroupConstraint) { 1091 GroupConstraint gc = (GroupConstraint)other; 1092 if (depth > 0 && !ignore.contains(gc)) 1093 gc.forwardCheck(assignment, support, conflicts, ignore, depth - 1); 1094 } else { 1095 other.computeConflicts(assignment, support, conflicts); 1096 } 1097 } 1098 for (GlobalConstraint<Lecture, Placement> other: getModel().globalConstraints()) { 1099 if (other instanceof WeakeningConstraint) continue; 1100 other.computeConflicts(assignment, support, conflicts); 1101 } 1102 1103 if (conflicts.contains(support)) 1104 conflicts.add(value); 1105 } 1106 } 1107 1108 if (canShareRoom() && neededSize > value.getRoomSize()) { 1109 // room is too small to fit all meet with classes 1110 conflicts.add(value); 1111 } 1112 1113 } finally { 1114 ignore.remove(this); 1115 } 1116 } 1117 1118 @Override 1119 public boolean inConflict(Assignment<Lecture, Placement> assignment, Placement value) { 1120 if (!isHard()) 1121 return false; 1122 for (Lecture v : variables()) { 1123 if (v.equals(value.variable())) 1124 continue; // ignore this variable 1125 Placement p = assignment.getValue(v); 1126 if (p == null) 1127 continue; // there is an unassigned variable -- great, still a chance to get violated 1128 if (!isSatisfiedPair(assignment, p, value)) 1129 return true; 1130 } 1131 if (getType().is(Flag.BACK_TO_BACK)) { 1132 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 1133 assignments.put(value.variable(), value); 1134 if (!isSatisfiedSeq(assignment, assignments, null)) 1135 return true; 1136 } 1137 if (getType().is(Flag.MAX_HRS_DAY)) { 1138 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 1139 assignments.put(value.variable(), value); 1140 for (int dayCode: Constants.DAY_CODES) { 1141 if (iMaxNHoursADayConsiderDatePatterns) { 1142 for (BitSet week: ((TimetableModel)getModel()).getWeeks()) { 1143 if (!value.getTimeLocation().shareWeeks(week)) continue; 1144 if (nrSlotsADay(assignment, dayCode, week, assignments, null) > getType().getMax()) 1145 return true; 1146 } 1147 } else { 1148 if (nrSlotsADay(assignment, dayCode, null, assignments, null) > getType().getMax()) return true; 1149 } 1150 } 1151 } 1152 1153 if (!forwardCheck(assignment, value, new HashSet<GroupConstraint>(), iForwardCheckMaxDepth - 1)) return true; 1154 1155 return false; 1156 } 1157 1158 public boolean forwardCheck(Assignment<Lecture, Placement> assignment, Placement value, Set<GroupConstraint> ignore, int depth) { 1159 try { 1160 if (depth < 0) return true; 1161 ignore.add(this); 1162 1163 int neededSize = value.variable().maxRoomUse(); 1164 1165 for (Lecture lecture: variables()) { 1166 if (lecture.equals(value.variable())) continue; // Skip this lecture 1167 Placement current = assignment.getValue(lecture); 1168 if (current != null) { // Has assignment, check whether it is conflicting 1169 if (isSatisfiedPair(assignment, value, current)) { 1170 // Increase needed size if the assignment is of the same room and overlapping in time 1171 if (canShareRoom() && sameRoomAndOverlaps(value, current)) { 1172 neededSize += lecture.maxRoomUse(); 1173 } 1174 continue; 1175 } 1176 return false; 1177 } 1178 1179 // Look for supporting assignments assignment 1180 boolean shareRoomAndOverlaps = canShareRoom(); 1181 Placement support = null; 1182 int nrSupports = 0; 1183 if (lecture.nrValues() >= iForwardCheckMaxDomainSize) { 1184 // ignore variables with large domains 1185 return true; 1186 } 1187 List<Placement> values = lecture.values(assignment); 1188 if (values.isEmpty()) { 1189 // ignore variables with empty domain 1190 return true; 1191 } 1192 for (Placement other: lecture.values(assignment)) { 1193 if (nrSupports < 2) { 1194 if (isSatisfiedPair(assignment, value, other)) { 1195 if (support == null) support = other; 1196 nrSupports ++; 1197 if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other)) 1198 shareRoomAndOverlaps = false; 1199 } 1200 } else if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other) && isSatisfiedPair(assignment, value, other)) { 1201 shareRoomAndOverlaps = false; 1202 } 1203 if (nrSupports > 1 && !shareRoomAndOverlaps) 1204 break; 1205 } 1206 1207 // No supporting assignment -> fail 1208 if (nrSupports == 0) { 1209 return false; // other class cannot be assigned with this value 1210 } 1211 // Increase needed size if all supporters are of the same room and in overlapping times 1212 if (shareRoomAndOverlaps) { 1213 neededSize += lecture.maxRoomUse(); 1214 } 1215 1216 // Only one supporter -> propagate the new assignment over other hard constraints of the lecture 1217 if (nrSupports == 1) { 1218 for (Constraint<Lecture, Placement> other: lecture.hardConstraints()) { 1219 if (other instanceof WeakeningConstraint) continue; 1220 if (other instanceof GroupConstraint) { 1221 GroupConstraint gc = (GroupConstraint)other; 1222 if (depth > 0 && !ignore.contains(gc) && !gc.forwardCheck(assignment, support, ignore, depth - 1)) return false; 1223 } else { 1224 if (other.inConflict(assignment, support)) return false; 1225 } 1226 } 1227 for (GlobalConstraint<Lecture, Placement> other: getModel().globalConstraints()) { 1228 if (other instanceof WeakeningConstraint) continue; 1229 if (other.inConflict(assignment, support)) return false; 1230 } 1231 } 1232 } 1233 1234 if (canShareRoom() && neededSize > value.getRoomSize()) { 1235 // room is too small to fit all meet with classes 1236 return false; 1237 } 1238 1239 return true; 1240 } finally { 1241 ignore.remove(this); 1242 } 1243 } 1244 1245 /** Constraint preference (0 if prohibited or required) 1246 * @return constraint preference (if soft) 1247 **/ 1248 public int getPreference() { 1249 return iPreference; 1250 } 1251 1252 /** 1253 * Current constraint preference (0 if prohibited or required, depends on 1254 * current satisfaction of the constraint) 1255 * @param assignment current assignment 1256 * @return current preference 1257 */ 1258 public int getCurrentPreference(Assignment<Lecture, Placement> assignment) { 1259 if (isHard()) return 0; // no preference 1260 if (countAssignedVariables(assignment) < 2) return - Math.abs(iPreference); // not enough variable 1261 if (getType().is(Flag.MAX_HRS_DAY)) { // max hours a day 1262 int over = 0; 1263 for (int dayCode: Constants.DAY_CODES) { 1264 if (iMaxNHoursADayConsiderDatePatterns) { 1265 for (BitSet week: ((TimetableModel)getModel()).getWeeks()) 1266 over += Math.max(0, nrSlotsADay(assignment, dayCode, week, null, null) - getType().getMax()); 1267 } else { 1268 over += Math.max(0, nrSlotsADay(assignment, dayCode, null, null, null) - getType().getMax()); 1269 } 1270 } 1271 return (over > 0 ? Math.abs(iPreference) * over / 12 : - Math.abs(iPreference)); 1272 } 1273 int nrViolatedPairs = 0; 1274 for (Lecture v1 : variables()) { 1275 Placement p1 = assignment.getValue(v1); 1276 if (p1 == null) continue; 1277 for (Lecture v2 : variables()) { 1278 Placement p2 = assignment.getValue(v2); 1279 if (p2 == null || v1.getId() >= v2.getId()) continue; 1280 if (!isSatisfiedPair(assignment, p1, p2)) nrViolatedPairs++; 1281 } 1282 } 1283 if (getType().is(Flag.BACK_TO_BACK)) { 1284 Set<Placement> conflicts = new HashSet<Placement>(); 1285 if (isSatisfiedSeq(assignment, new HashMap<Lecture, Placement>(), conflicts)) 1286 nrViolatedPairs += conflicts.size(); 1287 else 1288 nrViolatedPairs = variables().size(); 1289 } 1290 return (nrViolatedPairs > 0 ? Math.abs(iPreference) * nrViolatedPairs : - Math.abs(iPreference)); 1291 } 1292 1293 /** Current constraint preference change (if given placement is assigned) 1294 * @param assignment current assignment 1295 * @param placement placement that is being considered 1296 * @return change in the current preference, if assigned 1297 **/ 1298 public int getCurrentPreference(Assignment<Lecture, Placement> assignment, Placement placement) { 1299 if (isHard()) return 0; // no preference 1300 if (countAssignedVariables(assignment) + (assignment.getValue(placement.variable()) == null ? 1 : 0) < 2) return 0; // not enough variable 1301 if (getType().is(Flag.MAX_HRS_DAY)) { 1302 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 1303 assignments.put(placement.variable(), placement); 1304 HashMap<Lecture, Placement> unassignments = new HashMap<Lecture, Placement>(); 1305 unassignments.put(placement.variable(), null); 1306 int after = 0; 1307 int before = 0; 1308 for (int dayCode: Constants.DAY_CODES) { 1309 if (iMaxNHoursADayConsiderDatePatterns) { 1310 for (BitSet week: ((TimetableModel)getModel()).getWeeks()) { 1311 after += Math.max(0, nrSlotsADay(assignment, dayCode, week, assignments, null) - getType().getMax()); 1312 before += Math.max(0, nrSlotsADay(assignment, dayCode, week, unassignments, null) - getType().getMax()); 1313 } 1314 } else { 1315 after += Math.max(0, nrSlotsADay(assignment, dayCode, null, assignments, null) - getType().getMax()); 1316 before += Math.max(0, nrSlotsADay(assignment, dayCode, null, unassignments, null) - getType().getMax()); 1317 } 1318 } 1319 return (after > 0 ? Math.abs(iPreference) * after / 12 : - Math.abs(iPreference)) - (before > 0 ? Math.abs(iPreference) * before / 12 : - Math.abs(iPreference)); 1320 } 1321 1322 int nrViolatedPairsAfter = 0; 1323 int nrViolatedPairsBefore = 0; 1324 for (Lecture v1 : variables()) { 1325 for (Lecture v2 : variables()) { 1326 if (v1.getId() >= v2.getId()) continue; 1327 Placement p1 = (v1.equals(placement.variable()) ? null : assignment.getValue(v1)); 1328 Placement p2 = (v2.equals(placement.variable()) ? null : assignment.getValue(v2)); 1329 if (p1 != null && p2 != null && !isSatisfiedPair(assignment, p1, p2)) 1330 nrViolatedPairsBefore ++; 1331 if (v1.equals(placement.variable())) p1 = placement; 1332 if (v2.equals(placement.variable())) p2 = placement; 1333 if (p1 != null && p2 != null && !isSatisfiedPair(assignment, p1, p2)) 1334 nrViolatedPairsAfter ++; 1335 } 1336 } 1337 1338 if (getType().is(Flag.BACK_TO_BACK)) { 1339 HashMap<Lecture, Placement> assignments = new HashMap<Lecture, Placement>(); 1340 assignments.put(placement.variable(), placement); 1341 Set<Placement> conflicts = new HashSet<Placement>(); 1342 if (isSatisfiedSeq(assignment, assignments, conflicts)) 1343 nrViolatedPairsAfter += conflicts.size(); 1344 else 1345 nrViolatedPairsAfter = variables().size(); 1346 1347 HashMap<Lecture, Placement> unassignments = new HashMap<Lecture, Placement>(); 1348 unassignments.put(placement.variable(), null); 1349 Set<Placement> previous = new HashSet<Placement>(); 1350 if (isSatisfiedSeq(assignment, unassignments, previous)) 1351 nrViolatedPairsBefore += previous.size(); 1352 else 1353 nrViolatedPairsBefore = variables().size(); 1354 } 1355 1356 return (nrViolatedPairsAfter > 0 ? Math.abs(iPreference) * nrViolatedPairsAfter : - Math.abs(iPreference)) - 1357 (nrViolatedPairsBefore > 0 ? Math.abs(iPreference) * nrViolatedPairsBefore : - Math.abs(iPreference)); 1358 } 1359 1360 @Override 1361 public String toString() { 1362 StringBuffer sb = new StringBuffer(); 1363 sb.append(getName()); 1364 sb.append(" between "); 1365 for (Iterator<Lecture> e = variables().iterator(); e.hasNext();) { 1366 Lecture v = e.next(); 1367 sb.append(v.getName()); 1368 if (e.hasNext()) 1369 sb.append(", "); 1370 } 1371 return sb.toString(); 1372 } 1373 1374 @Override 1375 public boolean isHard() { 1376 return iIsRequired || iIsProhibited; 1377 } 1378 1379 @Override 1380 public String getName() { 1381 return getType().getName(); 1382 } 1383 1384 1385 private boolean isPrecedence(Placement p1, Placement p2, boolean firstGoesFirst, boolean considerDatePatterns) { 1386 int ord1 = variables().indexOf(p1.variable()); 1387 int ord2 = variables().indexOf(p2.variable()); 1388 TimeLocation t1 = null, t2 = null; 1389 if (ord1 < ord2) { 1390 if (firstGoesFirst) { 1391 t1 = p1.getTimeLocation(); 1392 t2 = p2.getTimeLocation(); 1393 } else { 1394 t2 = p1.getTimeLocation(); 1395 t1 = p2.getTimeLocation(); 1396 } 1397 } else { 1398 if (!firstGoesFirst) { 1399 t1 = p1.getTimeLocation(); 1400 t2 = p2.getTimeLocation(); 1401 } else { 1402 t2 = p1.getTimeLocation(); 1403 t1 = p2.getTimeLocation(); 1404 } 1405 } 1406 if (considerDatePatterns && iPrecedenceConsiderDatePatterns) { 1407 boolean sameDatePattern = (t1.getDatePatternId() != null ? t1.getDatePatternId().equals(t2.getDatePatternId()) : t1.getWeekCode().equals(t2.getWeekCode())); 1408 if (!sameDatePattern) { 1409 int m1 = t1.getFirstMeeting(iDayOfWeekOffset), m2 = t2.getFirstMeeting(iDayOfWeekOffset); 1410 if (m1 != m2) return m1 < m2; 1411 } 1412 } 1413 return t1.getStartSlots().nextElement() + t1.getLength() <= t2.getStartSlots().nextElement(); 1414 } 1415 1416 private static boolean isBackToBackDays(TimeLocation t1, TimeLocation t2) { 1417 int f1 = -1, f2 = -1, e1 = -1, e2 = -1; 1418 for (int i = 0; i < Constants.DAY_CODES.length; i++) { 1419 if ((t1.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1420 if (f1 < 0) 1421 f1 = i; 1422 e1 = i; 1423 } 1424 if ((t2.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1425 if (f2 < 0) 1426 f2 = i; 1427 e2 = i; 1428 } 1429 } 1430 return (e1 + 1 == f2) || (e2 + 1 == f1); 1431 } 1432 1433 private static boolean isNrDaysBetweenGreaterThanOne(TimeLocation t1, TimeLocation t2) { 1434 int f1 = -1, f2 = -1, e1 = -1, e2 = -1; 1435 for (int i = 0; i < Constants.DAY_CODES.length; i++) { 1436 if ((t1.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1437 if (f1 < 0) 1438 f1 = i; 1439 e1 = i; 1440 } 1441 if ((t2.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1442 if (f2 < 0) 1443 f2 = i; 1444 e2 = i; 1445 } 1446 } 1447 return (e1 - f2 > 2) || (e2 - f1 > 2); 1448 } 1449 1450 private boolean isFollowingDay(Placement p1, Placement p2, boolean firstGoesFirst) { 1451 int ord1 = variables().indexOf(p1.variable()); 1452 int ord2 = variables().indexOf(p2.variable()); 1453 TimeLocation t1 = null, t2 = null; 1454 if (ord1 < ord2) { 1455 if (firstGoesFirst) { 1456 t1 = p1.getTimeLocation(); 1457 t2 = p2.getTimeLocation(); 1458 } else { 1459 t2 = p1.getTimeLocation(); 1460 t1 = p2.getTimeLocation(); 1461 } 1462 } else { 1463 if (!firstGoesFirst) { 1464 t1 = p1.getTimeLocation(); 1465 t2 = p2.getTimeLocation(); 1466 } else { 1467 t2 = p1.getTimeLocation(); 1468 t1 = p2.getTimeLocation(); 1469 } 1470 } 1471 int f1 = -1, f2 = -1, e1 = -1; 1472 for (int i = 0; i < Constants.DAY_CODES.length; i++) { 1473 if ((t1.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1474 if (f1 < 0) 1475 f1 = i; 1476 e1 = i; 1477 } 1478 if ((t2.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1479 if (f2 < 0) 1480 f2 = i; 1481 } 1482 } 1483 return ((e1 + 1) % iNrWorkDays == f2); 1484 } 1485 1486 private boolean isEveryOtherDay(Placement p1, Placement p2, boolean firstGoesFirst) { 1487 int ord1 = variables().indexOf(p1.variable()); 1488 int ord2 = variables().indexOf(p2.variable()); 1489 TimeLocation t1 = null, t2 = null; 1490 if (ord1 < ord2) { 1491 if (firstGoesFirst) { 1492 t1 = p1.getTimeLocation(); 1493 t2 = p2.getTimeLocation(); 1494 } else { 1495 t2 = p1.getTimeLocation(); 1496 t1 = p2.getTimeLocation(); 1497 } 1498 } else { 1499 if (!firstGoesFirst) { 1500 t1 = p1.getTimeLocation(); 1501 t2 = p2.getTimeLocation(); 1502 } else { 1503 t2 = p1.getTimeLocation(); 1504 t1 = p2.getTimeLocation(); 1505 } 1506 } 1507 int f1 = -1, f2 = -1, e1 = -1; 1508 for (int i = 0; i < Constants.DAY_CODES.length; i++) { 1509 if ((t1.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1510 if (f1 < 0) 1511 f1 = i; 1512 e1 = i; 1513 } 1514 if ((t2.getDayCode() & Constants.DAY_CODES[i]) != 0) { 1515 if (f2 < 0) 1516 f2 = i; 1517 } 1518 } 1519 return ((e1 + 2) % iNrWorkDays == f2); 1520 } 1521 1522 private static boolean sameDays(int[] days1, int[] days2) { 1523 if (days2.length < days1.length) 1524 return sameDays(days2, days1); 1525 int i2 = 0; 1526 for (int i1 = 0; i1 < days1.length; i1++) { 1527 int d1 = days1[i1]; 1528 while (true) { 1529 if (i2 == days2.length) 1530 return false; 1531 int d2 = days2[i2]; 1532 if (d1 == d2) 1533 break; 1534 i2++; 1535 if (i2 == days2.length) 1536 return false; 1537 } 1538 i2++; 1539 } 1540 return true; 1541 } 1542 1543 private static boolean sameRoomAndOverlaps(Placement p1, Placement p2) { 1544 return p1.shareRooms(p2) && p1.getTimeLocation() != null && p2.getTimeLocation() != null && p1.getTimeLocation().hasIntersection(p2.getTimeLocation()); 1545 } 1546 1547 private static boolean sameHours(int start1, int len1, int start2, int len2) { 1548 if (len1 > len2) 1549 return sameHours(start2, len2, start1, len1); 1550 start1 %= Constants.SLOTS_PER_DAY; 1551 start2 %= Constants.SLOTS_PER_DAY; 1552 return (start1 >= start2 && start1 + len1 <= start2 + len2); 1553 } 1554 1555 private static boolean canFill(int totalGap, int gapMin, int gapMax, List<Integer> lengths) { 1556 if (gapMin <= totalGap && totalGap <= gapMax) 1557 return true; 1558 if (totalGap < 2 * gapMin) 1559 return false; 1560 for (int i = 0; i < lengths.size(); i++) { 1561 int length = lengths.get(i); 1562 lengths.remove(i); 1563 for (int gap = gapMin; gap <= gapMax; gap++) 1564 if (canFill(totalGap - gap - length, gapMin, gapMax, lengths)) 1565 return true; 1566 lengths.add(i, length); 1567 } 1568 return false; 1569 } 1570 1571 private boolean isSatisfiedSeq(Assignment<Lecture, Placement> assignment, HashMap<Lecture, Placement> assignments, Set<Placement> conflicts) { 1572 if (conflicts == null) 1573 return isSatisfiedSeqCheck(assignment, assignments, conflicts); 1574 else { 1575 Set<Placement> bestConflicts = isSatisfiedRecursive(assignment, 0, assignments, conflicts, 1576 new HashSet<Placement>(), null); 1577 if (bestConflicts == null) 1578 return false; 1579 conflicts.addAll(bestConflicts); 1580 return true; 1581 } 1582 } 1583 1584 private Set<Placement> isSatisfiedRecursive(Assignment<Lecture, Placement> assignment, int idx, HashMap<Lecture, Placement> assignments, 1585 Set<Placement> conflicts, Set<Placement> newConflicts, Set<Placement> bestConflicts) { 1586 if (idx == variables().size() && newConflicts.isEmpty()) 1587 return bestConflicts; 1588 if (isSatisfiedSeqCheck(assignment, assignments, conflicts)) { 1589 if (bestConflicts == null) { 1590 return new HashSet<Placement>(newConflicts); 1591 } else { 1592 int b = 0, n = 0; 1593 for (Placement value: assignments.values()) { 1594 if (value != null && bestConflicts.contains(value)) b++; 1595 if (value != null && newConflicts.contains(value)) n++; 1596 } 1597 if (n < b || (n == b && newConflicts.size() < bestConflicts.size())) 1598 return new HashSet<Placement>(newConflicts); 1599 } 1600 return bestConflicts; 1601 } 1602 if (idx == variables().size()) 1603 return bestConflicts; 1604 bestConflicts = isSatisfiedRecursive(assignment, idx + 1, assignments, conflicts, newConflicts, 1605 bestConflicts); 1606 Lecture lecture = variables().get(idx); 1607 //if (assignments != null && assignments.containsKey(lecture)) 1608 // return bestConflicts; 1609 Placement placement = null; 1610 if (assignments != null && assignments.containsKey(lecture)) 1611 placement = assignments.get(lecture); 1612 else if (assignment != null) 1613 placement = assignment.getValue(lecture); 1614 if (placement == null) 1615 return bestConflicts; 1616 if (conflicts != null && conflicts.contains(placement)) 1617 return bestConflicts; 1618 conflicts.add(placement); 1619 newConflicts.add(placement); 1620 bestConflicts = isSatisfiedRecursive(assignment, idx + 1, assignments, conflicts, newConflicts, bestConflicts); 1621 newConflicts.remove(placement); 1622 conflicts.remove(placement); 1623 return bestConflicts; 1624 } 1625 1626 private boolean isSatisfiedSeqCheck(Assignment<Lecture, Placement> assignment, HashMap<Lecture, Placement> assignments, Set<Placement> conflicts) { 1627 if (!getType().is(Flag.BACK_TO_BACK)) return true; 1628 int gapMin = getType().getMin(); 1629 int gapMax = getType().getMax(); 1630 1631 List<Integer> lengths = new ArrayList<Integer>(); 1632 1633 Placement[] res = new Placement[Constants.SLOTS_PER_DAY]; 1634 for (int i = 0; i < Constants.SLOTS_PER_DAY; i++) 1635 res[i] = null; 1636 1637 int nrLectures = 0; 1638 1639 for (Lecture lecture : variables()) { 1640 Placement placement = null; 1641 if (assignments != null && assignments.containsKey(lecture)) 1642 placement = assignments.get(lecture); 1643 else if (assignment != null) 1644 placement = assignment.getValue(lecture); 1645 if (placement == null) { 1646 if (!lecture.timeLocations().isEmpty()) 1647 lengths.add(lecture.timeLocations().get(0).getLength()); 1648 } else if (conflicts != null && conflicts.contains(placement)) { 1649 if (!lecture.timeLocations().isEmpty()) 1650 lengths.add(lecture.timeLocations().get(0).getLength()); 1651 } else { 1652 int pos = placement.getTimeLocation().getStartSlot(); 1653 int length = placement.getTimeLocation().getLength(); 1654 for (int j = pos; j < pos + length; j++) { 1655 if (res[j] != null) { 1656 if (conflicts == null) 1657 return false; 1658 if (!assignments.containsKey(lecture)) 1659 conflicts.add(placement); 1660 else if (!assignments.containsKey(res[j].variable())) 1661 conflicts.add(res[j]); 1662 } 1663 } 1664 for (int j = pos; j < pos + length; j++) 1665 res[j] = placement; 1666 nrLectures++; 1667 } 1668 } 1669 if (nrLectures <= 1) 1670 return true; 1671 1672 if (iIsRequired || (!iIsProhibited && iPreference < 0)) { 1673 int i = 0; 1674 Placement p = res[i]; 1675 while (p == null) 1676 p = res[++i]; 1677 i += res[i].getTimeLocation().getLength(); 1678 nrLectures--; 1679 while (nrLectures > 0) { 1680 int gap = 0; 1681 while (i < Constants.SLOTS_PER_DAY && res[i] == null) { 1682 gap++; 1683 i++; 1684 } 1685 if (i == Constants.SLOTS_PER_DAY) 1686 break; 1687 if (!canFill(gap, gapMin, gapMax, lengths)) 1688 return false; 1689 p = res[i]; 1690 i += res[i].getTimeLocation().getLength(); 1691 nrLectures--; 1692 } 1693 } else if (iIsProhibited || (!iIsRequired && iPreference > 0)) { 1694 int i = 0; 1695 Placement p = res[i]; 1696 while (p == null) 1697 p = res[++i]; 1698 i += res[i].getTimeLocation().getLength(); 1699 nrLectures--; 1700 while (nrLectures > 0) { 1701 int gap = 0; 1702 while (i < Constants.SLOTS_PER_DAY && res[i] == null) { 1703 gap++; 1704 i++; 1705 } 1706 if (i == Constants.SLOTS_PER_DAY) 1707 break; 1708 if ((gapMin == 0 || !canFill(gap, 0, gapMin - 1, lengths)) 1709 && (gapMax >= Constants.SLOTS_PER_DAY || !canFill(gap, gapMax + 1, Constants.SLOTS_PER_DAY, 1710 lengths))) { 1711 return false; 1712 } 1713 p = res[i]; 1714 i += res[i].getTimeLocation().getLength(); 1715 nrLectures--; 1716 } 1717 } 1718 return true; 1719 } 1720 1721 public boolean isSatisfied(Assignment<Lecture, Placement> assignment) { 1722 if (isHard()) return true; 1723 if (countAssignedVariables(assignment) < 2) return true; 1724 if (getPreference() == 0) return true; 1725 return isHard() || countAssignedVariables(assignment) < 2 || getPreference() == 0 || getCurrentPreference(assignment) < 0; 1726 } 1727 1728 public boolean isChildrenNotOverlap(Assignment<Lecture, Placement> assignment, Lecture lec1, Placement plc1, Lecture lec2, Placement plc2) { 1729 if (lec1.getSchedulingSubpartId().equals(lec2.getSchedulingSubpartId())) { 1730 // same subpart 1731 boolean overlap = plc1.getTimeLocation().hasIntersection(plc2.getTimeLocation()); 1732 1733 if (overlap && lec1.getParent() != null && variables().contains(lec1.getParent()) 1734 && lec2.getParent() != null && variables().contains(lec2.getParent())) { 1735 // children overlaps 1736 Placement p1 = assignment.getValue(lec1.getParent()); 1737 Placement p2 = assignment.getValue(lec2.getParent()); 1738 // parents not overlap, but children do 1739 if (p1 != null && p2 != null && !p1.getTimeLocation().hasIntersection(p2.getTimeLocation())) 1740 return false; 1741 } 1742 1743 if (!overlap && lec1.getChildrenSubpartIds() != null && lec2.getChildrenSubpartIds() != null) { 1744 // parents not overlap 1745 for (Long subpartId: lec1.getChildrenSubpartIds()) { 1746 for (Lecture c1 : lec1.getChildren(subpartId)) { 1747 Placement p1 = assignment.getValue(c1); 1748 if (p1 == null) continue; 1749 for (Lecture c2 : lec2.getChildren(subpartId)) { 1750 Placement p2 = assignment.getValue(c2); 1751 if (p2 == null) continue; 1752 if (!c1.getSchedulingSubpartId().equals(c2.getSchedulingSubpartId())) continue; 1753 // parents not overlap, but children do 1754 if (p1.getTimeLocation().hasIntersection(p2.getTimeLocation())) 1755 return false; 1756 } 1757 } 1758 } 1759 } 1760 } else { 1761 // different subpart 1762 } 1763 return true; 1764 } 1765 1766 public boolean isSatisfiedPair(Assignment<Lecture, Placement> assignment, Placement plc1, Placement plc2) { 1767 if (iIsRequired || (!iIsProhibited && iPreference <= 0)) 1768 return getType().isSatisfied(assignment, this, plc1, plc2); 1769 else if (iIsProhibited || (!iIsRequired && iPreference > 0)) 1770 return getType().isViolated(assignment, this, plc1, plc2); 1771 return true; 1772 } 1773 1774 public boolean canShareRoom() { 1775 return getType().is(Flag.CAN_SHARE_ROOM); 1776 } 1777 1778 private int nrSlotsADay(Assignment<Lecture, Placement> assignment, int dayCode, BitSet week, HashMap<Lecture, Placement> assignments, Set<Placement> conflicts) { 1779 Set<Integer> slots = new HashSet<Integer>(); 1780 for (Lecture lecture: variables()) { 1781 Placement placement = null; 1782 if (assignments != null && assignments.containsKey(lecture)) 1783 placement = assignments.get(lecture); 1784 else if (assignment != null) 1785 placement = assignment.getValue(lecture); 1786 if (placement == null || placement.getTimeLocation() == null) continue; 1787 if (conflicts != null && conflicts.contains(placement)) continue; 1788 TimeLocation t = placement.getTimeLocation(); 1789 if (t == null || (t.getDayCode() & dayCode) == 0 || (week != null && !t.shareWeeks(week))) continue; 1790 for (int i = 0; i < t.getLength(); i++) 1791 slots.add(i + t.getStartSlot()); 1792 } 1793 return slots.size(); 1794 } 1795 1796 @Override 1797 public boolean equals(Object o) { 1798 if (o == null || !(o instanceof GroupConstraint)) return false; 1799 return getGeneratedId() == ((GroupConstraint) o).getGeneratedId(); 1800 } 1801 1802 @Override 1803 public GroupConstraintContext createAssignmentContext(Assignment<Lecture, Placement> assignment) { 1804 return new GroupConstraintContext(assignment); 1805 } 1806 1807 public class GroupConstraintContext implements AssignmentConstraintContext<Lecture, Placement> { 1808 private int iLastPreference = 0; 1809 1810 public GroupConstraintContext(Assignment<Lecture, Placement> assignment) { 1811 updateCriterion(assignment); 1812 } 1813 1814 @Override 1815 public void assigned(Assignment<Lecture, Placement> assignment, Placement value) { 1816 updateCriterion(assignment); 1817 } 1818 1819 @Override 1820 public void unassigned(Assignment<Lecture, Placement> assignment, Placement value) { 1821 updateCriterion(assignment); 1822 } 1823 1824 private void updateCriterion(Assignment<Lecture, Placement> assignment) { 1825 if (!isHard()) { 1826 getModel().getCriterion(DistributionPreferences.class).inc(assignment, -iLastPreference); 1827 iLastPreference = getCurrentPreference(assignment) + Math.abs(iPreference); 1828 getModel().getCriterion(DistributionPreferences.class).inc(assignment, iLastPreference); 1829 } 1830 } 1831 1832 public int getPreference() { return iLastPreference; } 1833 } 1834}