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unionConst.hpp
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2 /*
3  * Main authors:
4  * Guido Tack <tack@gecode.org>
5  * Christian Schulte <schulte@gecode.org>
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8  * Guido Tack, 2004,2006,2007
9  * Christian Schulte, 2004
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35 
36 namespace Gecode { namespace Set { namespace Element {
37 
38  template<class SView, class RView>
41  ElementUnionConst(Home home, SView y0,
42  const IntSetArgs& iv0,
43  RView y1)
44  : Propagator(home), x0(y0), n_iv(iv0.size()), x1(y1) {
45  home.notice(*this,AP_DISPOSE);
46  x0.subscribe(home,*this, PC_SET_ANY);
47  x1.subscribe(home,*this, PC_SET_ANY);
48  iv=static_cast<Space&>(home).alloc<IntSet>(n_iv);
49  for (unsigned int i=iv0.size(); i--;)
50  iv[i]=iv0[i];
51  }
52 
53  template<class SView, class RView>
57  : Propagator(home,p), n_iv(p.n_iv) {
58  x0.update(home,p.x0);
59  x1.update(home,p.x1);
60  iv=home.alloc<IntSet>(n_iv);
61  for (unsigned int i=n_iv; i--;)
62  iv[i]=p.iv[i];
63  }
64 
65  template<class SView, class RView>
66  PropCost
68  return PropCost::linear(PropCost::HI, n_iv+2);
69  }
70 
71  template<class SView, class RView>
72  void
74  x0.reschedule(home,*this, PC_SET_ANY);
75  x1.reschedule(home,*this, PC_SET_ANY);
76  }
77 
78  template<class SView, class RView>
79  forceinline size_t
81  home.ignore(*this,AP_DISPOSE);
82  if (!home.failed()) {
83  x0.cancel(home,*this, PC_SET_ANY);
84  x1.cancel(home,*this, PC_SET_ANY);
85  }
86  for (unsigned int i=n_iv; i--;)
87  iv[i].~IntSet();
88  (void) Propagator::dispose(home);
89  return sizeof(*this);
90  }
91 
92  template<class SView, class RView>
95  post(Home home, SView x0, const IntSetArgs& xs,
96  RView x1) {
97  int n = xs.size();
98 
99  // s2 \subseteq {1,...,n}
100  Iter::Ranges::Singleton s(0, n-1);
101  GECODE_ME_CHECK(x1.intersectI(home,s));
102  (void) new (home)
103  ElementUnionConst<SView,RView>(home,x0,xs,x1);
104  return ES_OK;
105  }
106 
107  template<class SView, class RView>
108  Actor*
110  return new (home) ElementUnionConst<SView,RView>(home,*this);
111  }
112 
113  template<class SView, class RView>
114  ExecStatus
116  Region r;
117 
118  bool* stillSelected = r.alloc<bool>(n_iv);
119 
120  bool loopVar;
121  do {
122  loopVar = false;
123  for (int i=n_iv; i--;)
124  stillSelected[i] = false;
125 
126  // Cache the upper bound iterator, as we have to
127  // modify the upper bound while iterating
128  LubRanges<RView> x1ub(x1);
129  Iter::Ranges::Cache x1ubc(r,x1ub);
131  vx1ub(x1ubc);
132 
133  GlbRanges<RView> x1lb(x1);
134  Iter::Ranges::Cache x1lbc(r,x1lb);
136  vx1(x1lbc);
137 
138  // In the first iteration, compute in before[i] the union
139  // of all the upper bounds of the x_i. At the same time,
140  // exclude inconsistent x_i from x1.
141 
142  GLBndSet sofarBefore(home);
143  LUBndSet selectedInter(home, IntSet (Limits::min,
144  Limits::max));
145  GLBndSet* before =
146  static_cast<GLBndSet*>(r.ralloc(sizeof(GLBndSet)*n_iv));
147 
148  unsigned int maxCard = 0;
149  unsigned int minCard = Limits::card;
150 
151  while (vx1ub()) {
152  int i = vx1ub.val();
153 
154  IntSetRanges candCardR(iv[i]);
155  unsigned int candidateCard = Iter::Ranges::size(candCardR);
156 
157  IntSetRanges candlb(iv[i]);
158  LubRanges<SView> x0ub(x0);
160  LubRanges<SView> > diff(candlb, x0ub);
161 
162  bool selectSingleInconsistent = false;
163  if (x1.cardMax() <= 1) {
164  GlbRanges<SView> x0lb(x0);
165  IntSetRanges candub(iv[i]);
167  IntSetRanges > diff2(x0lb, candub);
168  selectSingleInconsistent = diff2() || candidateCard < x0.cardMin();
169  }
170 
171  // exclude inconsistent x_i
172  // an x_i is inconsistent if
173  // * at most one x_i can be selected and there are
174  // elements in x_0 that can't be in x_i
175  // (selectSingleInconsistent)
176  // * its min cardinality is greater than maxCard of x0
177  // * inter is not empty (there are elements in x_i
178  // that can't be in x_0)
179  if (selectSingleInconsistent ||
180  candidateCard > x0.cardMax() ||
181  diff()) {
182  ModEvent me = (x1.exclude(home,i));
183  loopVar |= me_modified(me);
184  GECODE_ME_CHECK(me);
185  } else {
186  stillSelected[i] = true;
187  // if x_i is consistent, check whether we know
188  // that its index is in x1
189  if (vx1() && vx1.val()==i) {
190  // x0 >= candidate, candidate <= x0
191  // GlbRanges<SView> candlb(candidate);
192  IntSetRanges candlb(iv[i]);
193  ModEvent me = x0.includeI(home,candlb);
194  loopVar |= me_modified(me);
195  GECODE_ME_CHECK(me);
196  ++vx1;
197  }
198  new (&before[i]) GLBndSet(home);
199  before[i].update(home,sofarBefore);
200  IntSetRanges cub(iv[i]);
201  sofarBefore.includeI(home,cub);
202  IntSetRanges clb(iv[i]);
203  selectedInter.intersectI(home,clb);
204  maxCard = std::max(maxCard, candidateCard);
205  minCard = std::min(minCard, candidateCard);
206  }
207 
208  ++vx1ub;
209  }
210 
211  if (x1.cardMax()==0) {
212  // Selector is empty, hence the result must be empty
213  {
214  GECODE_ME_CHECK(x0.cardMax(home,0));
215  }
216  for (int i=n_iv; i--;)
217  if (stillSelected[i])
218  before[i].dispose(home);
219  selectedInter.dispose(home);
220  sofarBefore.dispose(home);
221  return home.ES_SUBSUMED(*this);
222  }
223 
224  if (x1.cardMin() > 0) {
225  // Selector is not empty, hence the intersection of the
226  // possibly selected lower bounds is contained in x0
227  BndSetRanges si(selectedInter);
228  ModEvent me = x0.includeI(home, si);
229  loopVar |= me_modified(me);
230  GECODE_ME_CHECK(me);
231  me = x0.cardMin(home, minCard);
232  loopVar |= me_modified(me);
233  GECODE_ME_CHECK(me);
234  }
235  selectedInter.dispose(home);
236 
237  if (x1.cardMax() <= 1) {
238  ModEvent me = x0.cardMax(home, maxCard);
239  loopVar |= me_modified(me);
240  GECODE_ME_CHECK(me);
241  }
242 
243  {
244  // x0 <= sofarBefore
245  BndSetRanges sfB(sofarBefore);
246  ModEvent me = x0.intersectI(home,sfB);
247  loopVar |= me_modified(me);
248  GECODE_ME_CHECK(me);
249  }
250 
251  sofarBefore.dispose(home);
252 
253  GLBndSet sofarAfter(home);
254 
255  // In the second iteration, this time backwards, compute
256  // sofarAfter as the union of all lub(x_j) with j>i
257  for (int i=n_iv; i--;) {
258  if (!stillSelected[i])
259  continue;
260  BndSetRanges b(before[i]);
261  BndSetRanges s(sofarAfter);
262  GlbRanges<SView> x0lb(x0);
266  if (diff()) {
267  ModEvent me = (x1.include(home,i));
268  loopVar |= me_modified(me);
269  GECODE_ME_CHECK(me);
270 
271  // candidate != extra
272  IntSetRanges ivi(iv[i]);
273  if (!Iter::Ranges::subset(diff, ivi))
275  }
276 
277  IntSetRanges iviub(iv[i]);
278  sofarAfter.includeI(home,iviub);
279  before[i].dispose(home);
280  }
281  sofarAfter.dispose(home);
282 
283  } while (loopVar);
284 
285  if (x1.assigned()) {
286  assert(x0.assigned());
287  return home.ES_SUBSUMED(*this);
288  }
289 
290  return ES_FIX;
291  }
292 
293 }}}
294 
295 // STATISTICS: set-prop
void notice(Actor &a, ActorProperty p, bool duplicate=false)
Notice actor property.
Definition: core.hpp:3219
RView x1
Definition: element.hh:162
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: unionConst.hpp:80
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3563
bool includeI(Space &home, I &i)
Include the set represented by i in this set.
Definition: integerset.hpp:296
unsigned int size(I &i)
Size of all ranges of range iterator i.
bool intersectI(Space &home, I &i)
Exclude all elements not in the set represented by i from this set.
Definition: integerset.hpp:370
const int min
Smallest allowed integer in integer set.
Definition: set.hh:99
ElementUnionConst(Space &home, ElementUnionConst &p)
Constructor for cloning p.
Definition: unionConst.hpp:56
IntSet * iv
Definition: element.hh:160
const FloatNum min
Smallest allowed float value.
Definition: float.hh:846
Computation spaces.
Definition: core.hpp:1742
static PropCost linear(PropCost::Mod m, unsigned int n)
Linear complexity for modifier pcm and size measure n.
Definition: core.hpp:4796
Base-class for both propagators and branchers.
Definition: core.hpp:628
bool subset(I &i, J &j)
Check whether range iterator i is subset of range iterator j.
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: unionConst.hpp:109
int val(void) const
Return current value.
Range iterator for integer sets.
Definition: int.hh:292
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: unionConst.hpp:115
Gecode toplevel namespace
Base-class for propagators.
Definition: core.hpp:1064
Integer sets.
Definition: int.hh:174
const int max
Largest allowed integer in integer set.
Definition: set.hh:97
const unsigned int card
Maximum cardinality of an integer set.
Definition: set.hh:101
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function.
Definition: unionConst.hpp:67
Home class for posting propagators
Definition: core.hpp:856
Value iterator from range iterator.
Handle to region.
Definition: region.hpp:55
@ AP_DISPOSE
Actor must always be disposed.
Definition: core.hpp:562
Post propagator for SetVar SetOpType SetVar SetRelType r
Definition: set.hh:767
Range iterator for computing set difference.
Definition: ranges-diff.hpp:43
T * alloc(long unsigned int n)
Allocate block of n objects of type T from space heap.
Definition: core.hpp:2837
void update(Space &home, BndSet &x)
Update this set to be a clone of set x.
Definition: integerset.hpp:140
int n_iv
Definition: element.hh:161
struct Gecode::@602::NNF::@65::@66 b
For binary nodes (and, or, eqv)
Range iterator for the greatest lower bound.
Definition: var-imp.hpp:359
const Gecode::ModEvent ME_SET_FAILED
Domain operation has resulted in failure.
Definition: var-type.hpp:138
virtual void reschedule(Space &home)
Schedule function.
Definition: unionConst.hpp:73
int ModEvent
Type for modification events.
Definition: core.hpp:62
void dispose(Space &home)
Free memory used by this set.
Definition: integerset.hpp:60
Range iterator cache
Range iterator for computing union (binary)
bool failed(void) const
Check whether space is failed.
Definition: core.hpp:4044
const SetInstr * si[]
Definition: mm-set.cpp:4341
Propagation cost.
Definition: core.hpp:486
@ ES_FIX
Propagation has computed fixpoint.
Definition: core.hpp:477
Range iterator for the least upper bound.
Definition: var-imp.hpp:317
Range iterator for integer sets.
Definition: var-imp.hpp:185
#define forceinline
Definition: config.hpp:185
Growing sets of integers.
Definition: var-imp.hpp:205
const Gecode::PropCond PC_SET_ANY
Propagate when any bound or the cardinality of a view changes.
Definition: var-type.hpp:248
SView x0
Definition: element.hh:159
Range iterator for singleton range.
void ignore(Actor &a, ActorProperty p, bool duplicate=false)
Ignore actor property.
Definition: core.hpp:4074
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:52
virtual size_t dispose(Space &home)
Delete actor and return its size.
Definition: core.hpp:3252
bool me_modified(ModEvent me)
Check whether modification event me describes variable modification.
Definition: modevent.hpp:59
@ HI
Expensive.
Definition: core.hpp:514
Propagator for element with union of constant sets
Definition: element.hh:157
static ExecStatus post(Home home, SView z, const IntSetArgs &x, RView y)
Definition: unionConst.hpp:95
Shrinking sets of integers.
Definition: var-imp.hpp:243
int n
Number of negative literals for node type.
Definition: bool-expr.cpp:234
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
Gecode::IntArgs i({1, 2, 3, 4})
SetExpr inter(const SetVarArgs &x)
Intersection of set variables.
Definition: set-expr.cpp:696
@ ES_OK
Execution is okay.
Definition: core.hpp:476
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:232
const FloatNum max
Largest allowed float value.
Definition: float.hh:844
ExecStatus
Definition: core.hpp:472