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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 * Gabor Szokoli <szokoli@gecode.org>
6 *
7 * Copyright:
8 * Christian Schulte, 2003
9 * Gabor Szokoli, 2003
10 *
11 * This file is part of Gecode, the generic constraint
12 * development environment:
13 * http://www.gecode.org
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining
16 * a copy of this software and associated documentation files (the
17 * "Software"), to deal in the Software without restriction, including
18 * without limitation the rights to use, copy, modify, merge, publish,
19 * distribute, sublicense, and/or sell copies of the Software, and to
20 * permit persons to whom the Software is furnished to do so, subject to
21 * the following conditions:
22 *
23 * The above copyright notice and this permission notice shall be
24 * included in all copies or substantial portions of the Software.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
30 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
31 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
32 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
33 *
34 */
35
36namespace Gecode { namespace Int { namespace Rel {
37
38 /*
39 * Less or equal propagator
40 *
41 */
42
43 template<class V0, class V1>
44 forceinline
45 Lq<V0,V1>::Lq(Home home, V0 x0, V1 x1)
46 : MixBinaryPropagator<V0,PC_INT_BND,V1,PC_INT_BND>(home,x0,x1) {}
47
48 template<class V0, class V1>
49 ExecStatus
50 Lq<V0,V1>::post(Home home, V0 x0, V1 x1) {
51 GECODE_ME_CHECK(x0.lq(home,x1.max()));
52 GECODE_ME_CHECK(x1.gq(home,x0.min()));
53 if ((x0 != x1) && (x0.max() > x1.min()))
54 (void) new (home) Lq<V0,V1>(home,x0,x1);
55 return ES_OK;
56 }
57
58 template<class V0, class V1>
59 forceinline
60 Lq<V0,V1>::Lq(Space& home, Lq<V0,V1>& p)
61 : MixBinaryPropagator<V0,PC_INT_BND,V1,PC_INT_BND>(home,p) {}
62
63 template<class V0, class V1>
64 Actor*
65 Lq<V0,V1>::copy(Space& home) {
66 return new (home) Lq<V0,V1>(home,*this);
67 }
68
69 template<class V0, class V1>
70 ExecStatus
71 Lq<V0,V1>::propagate(Space& home, const ModEventDelta&) {
72 GECODE_ME_CHECK(x0.lq(home,x1.max()));
73 GECODE_ME_CHECK(x1.gq(home,x0.min()));
74 return (x0.max() <= x1.min()) ? home.ES_SUBSUMED(*this) : ES_FIX;
75 }
76
77
78
79
80 /*
81 * Less propagator
82 *
83 */
84 template<class V0, class V1>
85 forceinline
86 Le<V0,V1>::Le(Home home, V0 x0, V1 x1)
87 : MixBinaryPropagator<V0,PC_INT_BND,V1,PC_INT_BND>(home,x0,x1) {}
88
89 template<class V0, class V1>
90 ExecStatus
91 Le<V0,V1>::post(Home home, V0 x0, V1 x1) {
92 if (x0 == x1)
93 return ES_FAILED;
94 GECODE_ME_CHECK(x0.le(home,x1.max()));
95 GECODE_ME_CHECK(x1.gr(home,x0.min()));
96 if (x0.max() >= x1.min())
97 (void) new (home) Le<V0,V1>(home,x0,x1);
98 return ES_OK;
99 }
100
101 template<class V0, class V1>
102 forceinline
103 Le<V0,V1>::Le(Space& home, Le<V0,V1>& p)
104 : MixBinaryPropagator<V0,PC_INT_BND,V1,PC_INT_BND>(home,p) {}
105
106 template<class V0, class V1>
107 Actor*
108 Le<V0,V1>::copy(Space& home) {
109 return new (home) Le<V0,V1>(home,*this);
110 }
111
112 template<class V0, class V1>
113 ExecStatus
114 Le<V0,V1>::propagate(Space& home, const ModEventDelta&) {
115 GECODE_ME_CHECK(x0.le(home,x1.max()));
116 GECODE_ME_CHECK(x1.gr(home,x0.min()));
117 return (x0.max() < x1.min()) ? home.ES_SUBSUMED(*this) : ES_FIX;
118 }
119
120
121
122 /*
123 * Nary less and less or equal propagator
124 *
125 */
126
127 template<class View, int o>
128 forceinline
129 NaryLqLe<View,o>::Index::Index(Space& home, Propagator& p,
130 Council<Index>& c, int i0)
131 : Advisor(home,p,c), i(i0) {}
132
133 template<class View, int o>
134 forceinline
135 NaryLqLe<View,o>::Index::Index(Space& home, Index& a)
136 : Advisor(home,a), i(a.i) {}
137
138
139
140 template<class View, int o>
141 forceinline
142 NaryLqLe<View,o>::Pos::Pos(int p0, Pos* n)
143 : FreeList(n), p(p0) {}
144
145 template<class View, int o>
146 forceinline typename NaryLqLe<View,o>::Pos*
147 NaryLqLe<View,o>::Pos::next(void) const {
148 return static_cast<Pos*>(FreeList::next());
149 }
150
151 template<class View, int o>
152 forceinline void
153 NaryLqLe<View,o>::Pos::operator delete(void*) {}
154
155 template<class View, int o>
156 forceinline void
157 NaryLqLe<View,o>::Pos::operator delete(void*, Space&) {
158 GECODE_NEVER;
159 }
160
161 template<class View, int o>
162 forceinline void*
163 NaryLqLe<View,o>::Pos::operator new(size_t, Space& home) {
164 return home.fl_alloc<sizeof(Pos)>();
165 }
166
167 template<class View, int o>
168 forceinline void
169 NaryLqLe<View,o>::Pos::dispose(Space& home) {
170 home.fl_dispose<sizeof(Pos)>(this,this);
171 }
172
173
174 template<class View, int o>
175 forceinline bool
176 NaryLqLe<View,o>::empty(void) const {
177 return pos == nullptr;
178 }
179 template<class View, int o>
180 forceinline void
181 NaryLqLe<View,o>::push(Space& home, int p) {
182 // Try to avoid entering same position twice
183 if ((pos != nullptr) && (pos->p == p))
184 return;
185 pos = new (home) Pos(p,pos);
186 }
187 template<class View, int o>
188 forceinline int
189 NaryLqLe<View,o>::pop(Space& home) {
190 Pos* t = pos;
191 int p = t->p;
192 pos = pos->next();
193 t->dispose(home);
194 return p;
195 }
196
197 template<class View, int o>
198 forceinline
199 NaryLqLe<View,o>::NaryLqLe(Home home, ViewArray<View>& x)
200 : NaryPropagator<View,PC_INT_NONE>(home,x),
201 c(home), pos(nullptr), run(false), n_subsumed(0) {
202 for (int i=0; i<x.size(); i++)
203 x[i].subscribe(home, *new (home) Index(home,*this,c,i));
204 }
205
206 template<class View, int o>
207 ExecStatus
208 NaryLqLe<View,o>::post(Home home, ViewArray<View>& x) {
209 assert((o == 0) || (o == 1));
210 // Check for sharing
211 if (x.same()) {
212 if (o == 1)
213 return ES_FAILED;
214 /*
215 * Eliminate sharing: if a view occurs twice, all views in between
216 * must be equal.
217 */
218 int n = x.size();
219 for (int i=0; i<n; i++)
220 for (int j=n-1; j>i; j--)
221 if (x[i] == x[j]) {
222 if (i+1 != j) {
223 // Create equality propagator for elements i+1 ... j
224 ViewArray<View> y(home,j-i);
225 for (int k=j-i; k--; )
226 y[k] = x[i+1+k];
227 GECODE_ES_CHECK(NaryEqBnd<View>::post(home,y));
228 }
229 for (int k=0; k<n-1-j-1+1; k++)
230 x[i+1+k]=x[j+1+k];
231 n -= j-i;
232 break;
233 }
234 x.size(n);
235 }
236
237 // Propagate one round
238 for (int i=1; i<x.size(); i++)
239 GECODE_ME_CHECK(x[i].gq(home,x[i-1].min()+o));
240 for (int i=x.size()-1; i--;)
241 GECODE_ME_CHECK(x[i].lq(home,x[i+1].max()-o));
242 // Eliminate redundant variables
243 {
244 // Eliminate at beginning
245 {
246 int i=0;
247 while ((i+1 < x.size()) && (x[i].max()+o <= x[i+1].min()))
248 i++;
249 x.drop_fst(i);
250 }
251 // Eliminate at end
252 {
253 int i=x.size()-1;
254 while ((i > 0) && (x[i-1].max()+o <= x[i].min()))
255 i--;
256 x.drop_lst(i);
257 }
258 // Eliminate in the middle
259 if (x.size() > 1) {
260 int j=1;
261 for (int i=1; i+1<x.size(); i++)
262 if ((x[j-1].max()+o > x[i].min()) ||
263 (x[i].max()+o > x[i+1].min()))
264 x[j++]=x[i];
265 x[j++]=x[x.size()-1];
266 x.size(j);
267 }
268 }
269 if (x.size() == 2) {
270 if (o == 0)
271 return Lq<View,View>::post(home,x[0],x[1]);
272 else
273 return Le<View,View>::post(home,x[0],x[1]);
274 } else if (x.size() >= 2) {
275 (void) new (home) NaryLqLe<View,o>(home,x);
276 }
277 return ES_OK;
278 }
279
280 template<class View, int o>
281 forceinline
282 NaryLqLe<View,o>::NaryLqLe(Space& home, NaryLqLe<View,o>& p)
283 : NaryPropagator<View,PC_INT_NONE>(home,p),
284 pos(nullptr), run(false), n_subsumed(p.n_subsumed) {
285 assert(p.pos == nullptr);
286 c.update(home, p.c);
287 }
288
289 template<class View, int o>
290 Actor*
291 NaryLqLe<View,o>::copy(Space& home) {
292 if (n_subsumed > n_threshold) {
293 Region r;
294 // Record for which views there is an advisor
295 Support::BitSet<Region> a(r,static_cast<unsigned int>(x.size()));
296 for (Advisors<Index> as(c); as(); ++as)
297 a.set(static_cast<unsigned int>(as.advisor().i));
298 // Compact view array and compute map for advisors
299 int* m = r.alloc<int>(x.size());
300 int j=0;
301 for (int i=0; i<x.size(); i++)
302 if (a.get(static_cast<unsigned int>(i))) {
303 m[i] = j; x[j++] = x[i];
304 }
305 x.size(j);
306 // Remap advisors
307 for (Advisors<Index> as(c); as(); ++as)
308 as.advisor().i = m[as.advisor().i];
309
310 n_subsumed = 0;
311 }
312 return new (home) NaryLqLe<View,o>(home,*this);
313 }
314
315 template<class View, int o>
316 PropCost
317 NaryLqLe<View,o>::cost(const Space&, const ModEventDelta&) const {
318 return PropCost::binary(PropCost::HI);
319 }
320
321 template<class View, int o>
322 forceinline size_t
323 NaryLqLe<View,o>::dispose(Space& home) {
324 for (Advisors<Index> as(c); as(); ++as)
325 x[as.advisor().i].cancel(home,as.advisor());
326 c.dispose(home);
327 while (!empty())
328 (void) pop(home);
329 (void) NaryPropagator<View,PC_INT_NONE>::dispose(home);
330 return sizeof(*this);
331 }
332
333
334 template<class View, int o>
335 ExecStatus
336 NaryLqLe<View,o>::advise(Space& home, Advisor& _a, const Delta& d) {
337 Index& a = static_cast<Index&>(_a);
338 const int i = a.i;
339 switch (View::modevent(d)) {
340 case ME_INT_VAL:
341 a.dispose(home,c);
342 n_subsumed++;
343 break;
344 case ME_INT_BND:
345 if (((i == 0) || (x[i-1].max()+o <= x[i].min())) &&
346 ((i == x.size()-1) || (x[i].max()+o <= x[i+1].min()))) {
347 x[i].cancel(home,a);
348 a.dispose(home,c);
349 n_subsumed++;
350 return (run || (n_subsumed + 1 < x.size())) ? ES_FIX : ES_NOFIX;
351 }
352 break;
353 default:
354 return ES_FIX;
355 }
356 if (run)
357 return ES_FIX;
358 if (((i < x.size()-1) && (x[i+1].min() < x[i].min()+o)) ||
359 ((i > 0) && (x[i-1].max() > x[i].max()-o))) {
360 push(home,i);
361 return ES_NOFIX;
362 }
363 return (n_subsumed+1 >= x.size()) ? ES_NOFIX : ES_FIX;
364 }
365
366 template<class View, int o>
367 void
368 NaryLqLe<View,o>::reschedule(Space& home) {
369 View::schedule(home, *this, ME_INT_BND);
370 }
371
372 template<class View, int o>
373 ExecStatus
374 NaryLqLe<View,o>::propagate(Space& home, const ModEventDelta&) {
375 run = true;
376 int n = x.size();
377 while (!empty()) {
378 int p = pop(home);
379 for (int i=p; i<n-1; i++) {
380 ModEvent me = x[i+1].gq(home,x[i].min()+o);
381 if (me_failed(me))
382 return ES_FAILED;
383 if (!me_modified(me))
384 break;
385 }
386 for (int i=p; i>0; i--) {
387 ModEvent me = x[i-1].lq(home,x[i].max()-o);
388 if (me_failed(me))
389 return ES_FAILED;
390 if (!me_modified(me))
391 break;
392 }
393 }
394#ifdef GECODE_AUDIT
395 for (int i=0; i<n-1; i++)
396 assert(!me_modified(x[i+1].gq(home,x[i].min()+o)));
397 for (int i=n-1; i>0; i--)
398 assert(!me_modified(x[i-1].lq(home,x[i].max()-o)));
399#endif
400 if (n_subsumed+1 >= n)
401 return home.ES_SUBSUMED(*this);
402 run = false;
403 return ES_FIX;
404 }
405
406
407
408 /*
409 * Reified less or equal propagator
410 *
411 */
412
413 template<class View, class CtrlView, ReifyMode rm>
414 forceinline
415 ReLq<View,CtrlView,rm>::ReLq(Home home, View x0, View x1, CtrlView b)
416 : ReBinaryPropagator<View,PC_INT_BND,CtrlView>(home,x0,x1,b) {}
417
418 template<class View, class CtrlView, ReifyMode rm>
419 ExecStatus
420 ReLq<View,CtrlView,rm>::post(Home home, View x0, View x1, CtrlView b) {
421 if (b.one()) {
422 if (rm == RM_PMI)
423 return ES_OK;
424 return Lq<View,View>::post(home,x0,x1);
425 }
426 if (b.zero()) {
427 if (rm == RM_IMP)
428 return ES_OK;
429 return Le<View,View>::post(home,x1,x0);
430 }
431 if (x0 != x1) {
432 switch (rtest_lq(x0,x1)) {
433 case RT_TRUE:
434 if (rm != RM_IMP)
435 GECODE_ME_CHECK(b.one_none(home));
436 break;
437 case RT_FALSE:
438 if (rm != RM_PMI)
439 GECODE_ME_CHECK(b.zero_none(home));
440 break;
441 case RT_MAYBE:
442 (void) new (home) ReLq<View,CtrlView,rm>(home,x0,x1,b);
443 break;
444 default: GECODE_NEVER;
445 }
446 } else if (rm != RM_IMP) {
447 GECODE_ME_CHECK(b.one_none(home));
448 }
449 return ES_OK;
450 }
451
452 template<class View, class CtrlView, ReifyMode rm>
453 forceinline
454 ReLq<View,CtrlView,rm>::ReLq(Space& home, ReLq& p)
455 : ReBinaryPropagator<View,PC_INT_BND,CtrlView>(home,p) {}
456
457 template<class View, class CtrlView, ReifyMode rm>
458 Actor*
459 ReLq<View,CtrlView,rm>::copy(Space& home) {
460 return new (home) ReLq<View,CtrlView,rm>(home,*this);
461 }
462
463 template<class View, class CtrlView, ReifyMode rm>
464 ExecStatus
465 ReLq<View,CtrlView,rm>::propagate(Space& home, const ModEventDelta&) {
466 if (b.one()) {
467 if (rm != RM_PMI)
468 GECODE_REWRITE(*this,(Lq<View,View>::post(home(*this),x0,x1)));
469 } else if (b.zero()) {
470 if (rm != RM_IMP)
471 GECODE_REWRITE(*this,(Le<View,View>::post(home(*this),x1,x0)));
472 } else {
473 switch (rtest_lq(x0,x1)) {
474 case RT_TRUE:
475 if (rm != RM_IMP)
476 GECODE_ME_CHECK(b.one_none(home));
477 break;
478 case RT_FALSE:
479 if (rm != RM_PMI)
480 GECODE_ME_CHECK(b.zero_none(home));
481 break;
482 case RT_MAYBE:
483 return ES_FIX;
484 default: GECODE_NEVER;
485 }
486 }
487 return home.ES_SUBSUMED(*this);
488 }
489
490 /*
491 * Reified less or equal propagator involving one variable
492 *
493 */
494
495 template<class View, class CtrlView, ReifyMode rm>
496 forceinline
497 ReLqInt<View,CtrlView,rm>::ReLqInt(Home home, View x, int c0, CtrlView b)
498 : ReUnaryPropagator<View,PC_INT_BND,CtrlView>(home,x,b), c(c0) {}
499
500 template<class View, class CtrlView, ReifyMode rm>
501 ExecStatus
502 ReLqInt<View,CtrlView,rm>::post(Home home, View x, int c, CtrlView b) {
503 if (b.one()) {
504 if (rm != RM_PMI)
505 GECODE_ME_CHECK(x.lq(home,c));
506 } else if (b.zero()) {
507 if (rm != RM_IMP)
508 GECODE_ME_CHECK(x.gr(home,c));
509 } else {
510 switch (rtest_lq(x,c)) {
511 case RT_TRUE:
512 if (rm != RM_IMP)
513 GECODE_ME_CHECK(b.one_none(home));
514 break;
515 case RT_FALSE:
516 if (rm != RM_PMI)
517 GECODE_ME_CHECK(b.zero_none(home));
518 break;
519 case RT_MAYBE:
520 (void) new (home) ReLqInt<View,CtrlView,rm>(home,x,c,b);
521 break;
522 default: GECODE_NEVER;
523 }
524 }
525 return ES_OK;
526 }
527
528
529 template<class View, class CtrlView, ReifyMode rm>
530 forceinline
531 ReLqInt<View,CtrlView,rm>::ReLqInt(Space& home, ReLqInt& p)
532 : ReUnaryPropagator<View,PC_INT_BND,CtrlView>(home,p), c(p.c) {}
533
534 template<class View, class CtrlView, ReifyMode rm>
535 Actor*
536 ReLqInt<View,CtrlView,rm>::copy(Space& home) {
537 return new (home) ReLqInt<View,CtrlView,rm>(home,*this);
538 }
539
540 template<class View, class CtrlView, ReifyMode rm>
541 ExecStatus
542 ReLqInt<View,CtrlView,rm>::propagate(Space& home, const ModEventDelta&) {
543 if (b.one()) {
544 if (rm != RM_PMI)
545 GECODE_ME_CHECK(x0.lq(home,c));
546 } else if (b.zero()) {
547 if (rm != RM_IMP)
548 GECODE_ME_CHECK(x0.gr(home,c));
549 } else {
550 switch (rtest_lq(x0,c)) {
551 case RT_TRUE:
552 if (rm != RM_IMP)
553 GECODE_ME_CHECK(b.one_none(home));
554 break;
555 case RT_FALSE:
556 if (rm != RM_PMI)
557 GECODE_ME_CHECK(b.zero_none(home));
558 break;
559 case RT_MAYBE:
560 return ES_FIX;
561 default: GECODE_NEVER;
562 }
563 }
564 return home.ES_SUBSUMED(*this);
565 }
566
567}}}
568
569// STATISTICS: int-prop
570