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nroot.hpp
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4  * Christian Schulte <schulte@gecode.org>
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7  * Christian Schulte, 2012
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33 
34 #include <gecode/int/rel.hh>
35 
36 #include <climits>
37 #include <algorithm>
38 
39 namespace Gecode { namespace Int { namespace Arithmetic {
40 
41  /*
42  * Positive bounds consistent nth root
43  *
44  */
45 
46  template<class Ops, bool minus>
48  prop_nroot_plus_bnd(Space& home, IntView x0, IntView x1, const Ops& ops) {
49  if (minus) {
50  bool mod;
51  do {
52  mod = false;
53  {
54  ModEvent me = x1.gq(home,-ops.cnroot(-x0.min()));
55  if (me_failed(me)) return ES_FAILED;
56  mod |= me_modified(me);
57  }
58  {
59  ModEvent me = x1.lq(home,-ops.cnroot(-x0.max()));
60  if (me_failed(me)) return ES_FAILED;
61  mod |= me_modified(me);
62  }
63  {
64  ModEvent me = x0.gq(home,-ops.tpow(-x1.min()));
65  if (me_failed(me)) return ES_FAILED;
66  mod |= me_modified(me);
67  }
68  {
69  ModEvent me = x0.lq(home,-(ops.tpow(-x1.max()-1)+1));
70  if (me_failed(me)) return ES_FAILED;
71  mod |= me_modified(me);
72  }
73  } while (mod);
74  } else {
75  bool mod;
76  do {
77  mod = false;
78  {
79  ModEvent me = x1.lq(home,ops.fnroot(x0.max()));
80  if (me_failed(me)) return ES_FAILED;
81  mod |= me_modified(me);
82  }
83  {
84  ModEvent me = x1.gq(home,ops.fnroot(x0.min()));
85  if (me_failed(me)) return ES_FAILED;
86  mod |= me_modified(me);
87  }
88  {
89  ModEvent me = x0.le(home,ops.tpow(x1.max()+1));
90  if (me_failed(me)) return ES_FAILED;
91  mod |= me_modified(me);
92  }
93  {
94  ModEvent me = x0.gq(home,ops.tpow(x1.min()));
95  if (me_failed(me)) return ES_FAILED;
96  mod |= me_modified(me);
97  }
98  } while (mod);
99  }
100  return ES_OK;
101  }
102 
103  template<class Ops, bool minus>
106  const Ops& o)
107  : BinaryPropagator<IntView,PC_INT_BND>(home,x0,x1),
108  ops(o) {}
109 
110  template<class Ops, bool minus>
113  if (minus) {
114  GECODE_ME_CHECK(x0.lq(home,0));
115  GECODE_ME_CHECK(x1.lq(home,0));
116  } else {
117  GECODE_ME_CHECK(x0.gq(home,0));
118  GECODE_ME_CHECK(x1.gq(home,0));
119  }
120  (void) new (home) NrootPlusBnd<Ops,minus>(home,x0,x1,ops);
121  return ES_OK;
122  }
123 
124  template<class Ops, bool minus>
129  ops(p.ops) {}
130 
131  template<class Ops, bool minus>
132  Actor*
134  return new (home) NrootPlusBnd<Ops,minus>(home,*this);
135  }
136 
137  template<class Ops, bool minus>
138  ExecStatus
140  GECODE_ES_CHECK((prop_nroot_plus_bnd<Ops,minus>(home,x0,x1,ops)));
141  return x1.assigned() ? home.ES_SUBSUMED(*this) : ES_FIX;
142  }
143 
144 
145  /*
146  * Bounds consistent nth root
147  *
148  */
149 
150  template<class Ops>
152  prop_nroot_bnd(Space& home, IntView x0, IntView x1, const Ops& ops) {
153  assert((x0.min() < 0) && (x0.max() > 0));
154  assert((x1.min() < 0) && (x1.max() > 0));
155 
156  GECODE_ME_CHECK(x1.lq(home,ops.fnroot(x0.max())));
157  GECODE_ME_CHECK(x1.gq(home,-ops.cnroot(-x0.min())));
158  GECODE_ME_CHECK(x0.le(home,ops.tpow(x1.max()+1)));
159  GECODE_ME_CHECK(x0.gq(home,ops.tpow(x1.min()-1)+1));
160 
161  return ES_OK;
162  }
163 
164  template<class Ops>
166  NrootBnd<Ops>::NrootBnd(Home home, IntView x0, IntView x1, const Ops& o)
167  : BinaryPropagator<IntView,PC_INT_BND>(home,x0,x1),
168  ops(o) {}
169 
170  template<class Ops>
172  NrootBnd<Ops>::post(Home home, IntView x0, IntView x1, Ops ops) {
173  if (static_cast<unsigned int>(ops.exp()) >= sizeof(int) * CHAR_BIT) {
174  // The integer limits allow only -2, -1, 0, 1 for x1
175  GECODE_ME_CHECK(x1.lq(home,1));
176  GECODE_ME_CHECK(x1.gq(home,-2));
177  // Just rewrite to values that can be handeled without overflow
178  ops.exp(ops.even() ? 30 : 31);
179  }
180 
181  if (ops.exp() == 0) {
182  GECODE_ME_CHECK(x1.eq(home,1));
183  return ES_OK;
184  } else if (ops.exp() == 1) {
185  return Rel::EqBnd<IntView,IntView>::post(home,x0,x1);
186  }
187 
188  if (x0 == x1) {
189  assert(ops.exp() > 1);
190  GECODE_ME_CHECK(x0.lq(home,1));
191  GECODE_ME_CHECK(x0.gq(home,ops.even() ? 0 : -2));
192  return ES_OK;
193  }
194 
195  // Limits values such that no overflow can occur
196  GECODE_ME_CHECK(x1.lq(home,ops.fnroot(Limits::max)));
197  GECODE_ME_CHECK(x1.gq(home,-ops.cnroot(-Limits::min)));
198 
199  if (ops.even()) {
200  GECODE_ME_CHECK(x0.gq(home,0));
201  GECODE_ME_CHECK(x1.gq(home,0));
202  }
203 
204  if ((x0.min() >= 0) || (x1.min() >= 0))
205  return NrootPlusBnd<Ops,false>::post(home,x0,x1,ops);
206 
207  if ((x0.max() <= 0) || (x1.max() <= 0))
208  return NrootPlusBnd<Ops,true>::post(home,x0,x1,ops);
209 
210  assert((x0.min() < 0) && (x0.max() > 0));
211  assert((x1.min() < 0) && (x1.max() > 0));
212  GECODE_ES_CHECK(prop_nroot_bnd<Ops>(home,x0,x1,ops));
213  (void) new (home) NrootBnd(home,x0,x1,ops);
214  return ES_OK;
215  }
216 
217  template<class Ops>
221  ops(p.ops) {}
222 
223  template<class Ops>
224  Actor*
226  return new (home) NrootBnd<Ops>(home,*this);
227  }
228 
229  template<class Ops>
230  ExecStatus
232  assert(!ops.even());
233  if ((x0.min() >= 0) || (x1.min() >= 0))
234  GECODE_REWRITE(*this,(NrootPlusBnd<Ops,false>::post(home(*this),x0,x1,ops)));
235 
236  if ((x0.max() <= 0) || (x1.max() <= 0))
237  GECODE_REWRITE(*this,(NrootPlusBnd<Ops,true>::post(home(*this),x0,x1,ops)));
238 
239  GECODE_ES_CHECK(prop_nroot_bnd(home,x0,x1,ops));
240 
241  return x0.assigned() && x1.assigned() ? home.ES_SUBSUMED(*this) : ES_NOFIX;
242  }
243 
244 
245  /*
246  * Domain consistent nth root
247  *
248  */
250  template<class Ops>
251  class RangesMapPow {
252  protected:
254  Ops ops;
255  public:
257  forceinline RangesMapPow(const Ops& o) : ops(o) {}
259  forceinline int min(int x) const {
260  return ops.tpow(x);
261  }
263  forceinline int max(int x) const {
264  return ops.tpow(x+1)-1;
265  }
266  };
267 
269  template<class Ops>
271  protected:
273  Ops ops;
274  public:
276  forceinline RangesMapNroot(const Ops& o) : ops(o) {}
278  forceinline int min(int x) const {
279  return (x < 0) ? -ops.cnroot(-x) : ops.fnroot(x);
280  }
282  forceinline int max(int x) const {
283  return (x < 0) ? -ops.cnroot(-x) : ops.fnroot(x);
284  }
285  };
286 
287  template<class Ops, bool minus>
290  const Ops& o)
291  : BinaryPropagator<IntView,PC_INT_DOM>(home,x0,x1),
292  ops(o) {}
293 
294  template<class Ops, bool minus>
297  if (minus) {
298  GECODE_ME_CHECK(x0.lq(home,0));
299  GECODE_ME_CHECK(x1.lq(home,0));
300  } else {
301  GECODE_ME_CHECK(x0.gq(home,0));
302  GECODE_ME_CHECK(x1.gq(home,0));
303  }
304  GECODE_ES_CHECK((prop_nroot_plus_bnd<Ops,minus>(home,x0,x1,ops)));
305  (void) new (home) NrootPlusDom<Ops,minus>(home,x0,x1,ops);
306  return ES_OK;
307  }
308 
309  template<class Ops, bool minus>
314  ops(p.ops) {}
315 
316  template<class Ops, bool minus>
317  Actor*
319  return new (home) NrootPlusDom<Ops,minus>(home,*this);
320  }
321 
322  template<class Ops, bool minus>
323  PropCost
325  if (IntView::me(med) == ME_INT_VAL)
327  else if (IntView::me(med) == ME_INT_DOM)
329  else
331  }
332 
333  template<class Ops, bool minus>
334  ExecStatus
336  if (IntView::me(med) != ME_INT_DOM) {
337  GECODE_ES_CHECK((prop_nroot_plus_bnd<Ops,minus>(home,x0,x1,ops)));
338  return x1.assigned() ? home.ES_SUBSUMED(*this)
340  }
341 
342  {
344  RangesMapNroot<Ops> rmn(ops);
346  m(r,rmn);
347  GECODE_ME_CHECK(x1.inter_r(home,m,false));
348  }
349 
350  {
352  RangesMapPow<Ops> rmp(ops);
354  m(r,rmp);
355  GECODE_ME_CHECK(x0.inter_r(home,m,false));
356  }
357 
358  return x1.assigned() ? home.ES_SUBSUMED(*this) : ES_FIX;
359  }
360 
361 
362 
363  template<class Ops>
365  NrootDom<Ops>::NrootDom(Home home, IntView x0, IntView x1, const Ops& o)
366  : BinaryPropagator<IntView,PC_INT_DOM>(home,x0,x1),
367  ops(o) {}
368 
369  template<class Ops>
371  NrootDom<Ops>::post(Home home, IntView x0, IntView x1, Ops ops) {
372  if (static_cast<unsigned int>(ops.exp()) >= sizeof(int) * CHAR_BIT) {
373  // The integer limits allow only -2, -1, 0, 1 for x1
374  GECODE_ME_CHECK(x1.lq(home,1));
375  GECODE_ME_CHECK(x1.gq(home,-2));
376  // Just rewrite to values that can be handeled without overflow
377  ops.exp(ops.even() ? 30 : 31);
378  }
379 
380  if (ops.exp() == 0) {
381  GECODE_ME_CHECK(x1.eq(home,1));
382  return ES_OK;
383  } else if (ops.exp() == 1) {
384  return Rel::EqDom<IntView,IntView>::post(home,x0,x1);
385  }
386 
387  if (x0 == x1) {
388  assert(ops.exp() > 1);
389  GECODE_ME_CHECK(x0.lq(home,1));
390  GECODE_ME_CHECK(x0.gq(home,ops.even() ? 0 : -2));
391  return ES_OK;
392  }
393 
394  // Limits values such that no overflow can occur
395  GECODE_ME_CHECK(x1.lq(home,ops.fnroot(Limits::max)));
396  GECODE_ME_CHECK(x1.gq(home,-ops.cnroot(-Limits::min)));
397 
398  if (ops.even()) {
399  GECODE_ME_CHECK(x0.gq(home,0));
400  GECODE_ME_CHECK(x1.gq(home,0));
401  }
402 
403  if ((x0.min() >= 0) || (x1.min() >= 0))
404  return NrootPlusDom<Ops,false>::post(home,x0,x1,ops);
405 
406  if ((x0.max() <= 0) || (x1.max() <= 0))
407  return NrootPlusDom<Ops,true>::post(home,x0,x1,ops);
408 
409  assert((x0.min() < 0) && (x0.max() > 0));
410  assert((x1.min() < 0) && (x1.max() > 0));
411  GECODE_ES_CHECK(prop_nroot_bnd<Ops>(home,x0,x1,ops));
412  (void) new (home) NrootDom(home,x0,x1,ops);
413  return ES_OK;
414  }
415 
416  template<class Ops>
420  ops(p.ops) {}
421 
422  template<class Ops>
423  Actor*
425  return new (home) NrootDom<Ops>(home,*this);
426  }
427 
428  template<class Ops>
429  PropCost
430  NrootDom<Ops>::cost(const Space&, const ModEventDelta& med) const {
431  if (IntView::me(med) == ME_INT_VAL)
433  else if (IntView::me(med) == ME_INT_DOM)
435  else
437  }
438 
439  template<class Ops>
440  ExecStatus
442  assert(!ops.even());
443  if ((x0.min() >= 0) || (x1.min() >= 0))
444  GECODE_REWRITE(*this,(NrootPlusDom<Ops,false>::post(home(*this),x0,x1,ops)));
445 
446  if ((x0.max() <= 0) || (x1.max() <= 0))
447  GECODE_REWRITE(*this,(NrootPlusDom<Ops,true>::post(home(*this),x0,x1,ops)));
448 
449  if (IntView::me(med) != ME_INT_DOM) {
450  GECODE_ES_CHECK(prop_nroot_bnd<Ops>(home,x0,x1,ops));
451  return x0.assigned() && x1.assigned() ? home.ES_SUBSUMED(*this)
453  }
454 
455  {
457  RangesMapNroot<Ops> rmn(ops);
459  m(r,rmn);
460  GECODE_ME_CHECK(x1.inter_r(home,m,false));
461  }
462 
463  {
465  RangesMapPow<Ops> rmp(ops);
467  m(r,rmp);
468  GECODE_ME_CHECK(x0.inter_r(home,m,false));
469  }
470 
471  return x0.assigned() && x1.assigned() ? home.ES_SUBSUMED(*this) : ES_FIX;
472  }
473 
474 
475 }}}
476 
477 // STATISTICS: int-prop
478 
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:232
Node * x
Pointer to corresponding Boolean expression node.
Definition: bool-expr.cpp:249
NNF * r
Right subtree.
Definition: bool-expr.cpp:242
Base-class for both propagators and branchers.
Definition: core.hpp:628
Binary propagator.
Definition: pattern.hpp:84
Home class for posting propagators
Definition: core.hpp:856
Bounds consistent n-th root propagator.
Definition: arithmetic.hh:520
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: nroot.hpp:231
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: nroot.hpp:225
NrootBnd(Space &home, NrootBnd< Ops > &p)
Constructor for cloning p.
Definition: nroot.hpp:219
static ExecStatus post(Home home, IntView x0, IntView x1, Ops ops)
Post propagator.
Definition: nroot.hpp:172
Domain consistent n-th root propagator.
Definition: arithmetic.hh:580
NrootDom(Space &home, NrootDom< Ops > &p)
Constructor for cloning p.
Definition: nroot.hpp:418
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function.
Definition: nroot.hpp:430
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: nroot.hpp:441
static ExecStatus post(Home home, IntView x0, IntView x1, Ops ops)
Post propagator.
Definition: nroot.hpp:371
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: nroot.hpp:424
Positive bounds consistent n-th root propagator.
Definition: arithmetic.hh:494
NrootPlusBnd(Space &home, NrootPlusBnd< Ops, minus > &p)
Constructor for cloning p.
Definition: nroot.hpp:126
static ExecStatus post(Home home, IntView x0, IntView x1, Ops ops)
Post propagator.
Definition: nroot.hpp:112
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: nroot.hpp:133
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: nroot.hpp:139
Domain consistent n-th root propagator.
Definition: arithmetic.hh:546
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: nroot.hpp:318
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: nroot.hpp:335
static ExecStatus post(Home home, IntView x0, IntView x1, Ops ops)
Post propagator.
Definition: nroot.hpp:296
NrootPlusDom(Space &home, NrootPlusDom< Ops, minus > &p)
Constructor for cloning p.
Definition: nroot.hpp:311
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function.
Definition: nroot.hpp:324
Mapping integer to n-th root.
Definition: nroot.hpp:270
int max(int x) const
Perform mapping of maximum.
Definition: nroot.hpp:282
RangesMapNroot(const Ops &o)
Initialize with operations o.
Definition: nroot.hpp:276
int min(int x) const
Perform mapping of minimum.
Definition: nroot.hpp:278
Mapping ranges to powers.
Definition: nroot.hpp:251
int min(int x) const
Perform mapping of minimum.
Definition: nroot.hpp:259
RangesMapPow(const Ops &o)
Initialize with operations o.
Definition: nroot.hpp:257
int max(int x) const
Perform mapping of maximum.
Definition: nroot.hpp:263
Integer view for integer variables.
Definition: view.hpp:129
int min(void) const
Return minimum of domain.
Definition: int.hpp:58
ModEvent lq(Space &home, int n)
Restrict domain values to be less or equal than n.
Definition: int.hpp:121
int med(void) const
Return median of domain (greatest element not greater than the median)
Definition: int.hpp:66
ModEvent le(Space &home, int n)
Restrict domain values to be less than n.
Definition: int.hpp:130
ModEvent gq(Space &home, int n)
Restrict domain values to be greater or equal than n.
Definition: int.hpp:139
int max(void) const
Return maximum of domain.
Definition: int.hpp:62
ModEvent eq(Space &home, int n)
Restrict domain values to be equal to n.
Definition: int.hpp:166
static ExecStatus post(Home home, View0 x0, View1 x1)
Post bounds consistent propagator .
Definition: eq.hpp:108
static ExecStatus post(Home home, View0 x0, View1 x1)
Post domain consistent propagator .
Definition: eq.hpp:176
Range iterator for integer variable views
Definition: int.hpp:246
Range iterator for mapping ranges.
Definition: ranges-map.hpp:45
Propagation cost.
Definition: core.hpp:486
static PropCost unary(PropCost::Mod m)
Single variable for modifier pcm.
Definition: core.hpp:4813
static PropCost binary(PropCost::Mod m)
Two variables for modifier pcm.
Definition: core.hpp:4809
@ LO
Cheap.
Definition: core.hpp:513
@ HI
Expensive.
Definition: core.hpp:514
Computation spaces.
Definition: core.hpp:1742
static ModEvent me(const ModEventDelta &med)
Return modification event for view type in med.
Definition: view.hpp:552
ExecStatus
Definition: core.hpp:472
@ ES_OK
Execution is okay.
Definition: core.hpp:476
@ ES_FIX
Propagation has computed fixpoint.
Definition: core.hpp:477
@ ES_FAILED
Execution has resulted in failure.
Definition: core.hpp:474
@ ES_NOFIX
Propagation has not computed fixpoint.
Definition: core.hpp:475
int ModEvent
Type for modification events.
Definition: core.hpp:62
void mod(Home home, IntVar x0, IntVar x1, IntVar x2, IntPropLevel ipl)
Post propagator for .
Definition: arithmetic.cpp:360
ExecStatus ES_NOFIX_PARTIAL(Propagator &p, const ModEventDelta &med)
Propagator p has not computed partial fixpoint
Definition: core.hpp:3576
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3563
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:52
#define GECODE_REWRITE(prop, post)
Rewrite propagator by executing post function.
Definition: macros.hpp:116
bool me_failed(ModEvent me)
Check whether modification event me is failed.
Definition: modevent.hpp:54
#define GECODE_ES_CHECK(es)
Check whether execution status es is failed or subsumed, and forward failure or subsumption.
Definition: macros.hpp:91
bool me_modified(ModEvent me)
Check whether modification event me describes variable modification.
Definition: modevent.hpp:59
ExecStatus prop_nroot_bnd(Space &home, IntView x0, IntView x1, const Ops &ops)
Definition: nroot.hpp:152
ExecStatus prop_nroot_plus_bnd(Space &home, IntView x0, IntView x1, const Ops &ops)
Definition: nroot.hpp:48
const int min
Smallest allowed integer value.
Definition: int.hh:118
const int max
Largest allowed integer value.
Definition: int.hh:116
const Gecode::PropCond PC_INT_BND
Propagate when minimum or maximum of a view changes.
Definition: var-type.hpp:91
const Gecode::PropCond PC_INT_DOM
Propagate when domain changes.
Definition: var-type.hpp:100
const Gecode::ModEvent ME_INT_VAL
Domain operation has resulted in a value (assigned variable)
Definition: var-type.hpp:56
const Gecode::ModEvent ME_INT_DOM
Domain operation has changed the domain.
Definition: var-type.hpp:72
#define forceinline
Definition: config.hpp:192