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re-eq.hpp
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1 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2 /*
3  * Main authors:
4  * Guido Tack <tack@gecode.org>
5  * Christian Schulte <schulte@gecode.org>
6  *
7  * Bugfixes provided by:
8  * Grégoire Dooms <dooms@info.ucl.ac.be>
9  *
10  * Copyright:
11  * Guido Tack, 2004
12  * Christian Schulte, 2004
13  *
14  * This file is part of Gecode, the generic constraint
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38 
39 namespace Gecode { namespace Set { namespace Rel {
40 
41  template<class View0, class View1, class CtrlView, ReifyMode rm>
43  ReEq<View0,View1,CtrlView,rm>::ReEq(Home home, View0 y0, View1 y1,
44  CtrlView y2)
45  : Propagator(home), x0(y0), x1(y1), b(y2) {
46  b.subscribe(home,*this, Gecode::Int::PC_INT_VAL);
47  x0.subscribe(home,*this, PC_SET_ANY);
48  x1.subscribe(home,*this, PC_SET_ANY);
49  }
50 
51  template<class View0, class View1, class CtrlView, ReifyMode rm>
54  : Propagator(home,p) {
55  x0.update(home,p.x0);
56  x1.update(home,p.x1);
57  b.update(home,p.b);
58  }
59 
60  template<class View0, class View1, class CtrlView, ReifyMode rm>
61  PropCost
64  }
65 
66  template<class View0, class View1, class CtrlView, ReifyMode rm>
67  void
69  b.reschedule(home,*this, Gecode::Int::PC_INT_VAL);
70  x0.reschedule(home,*this, PC_SET_ANY);
71  x1.reschedule(home,*this, PC_SET_ANY);
72  }
73 
74  template<class View0, class View1, class CtrlView, ReifyMode rm>
75  forceinline size_t
77  b.cancel(home,*this, Gecode::Int::PC_INT_VAL);
78  x0.cancel(home,*this, PC_SET_ANY);
79  x1.cancel(home,*this, PC_SET_ANY);
80  (void) Propagator::dispose(home);
81  return sizeof(*this);
82  }
83 
84  template<class View0, class View1, class CtrlView, ReifyMode rm>
86  ReEq<View0,View1,CtrlView,rm>::post(Home home, View0 x0, View1 x1,
87  CtrlView b) {
88  if (!same(x0,x1)) {
89  (void) new (home) ReEq<View0,View1,CtrlView,rm>(home,x0,x1,b);
90  } else if (rm != RM_IMP) {
91  GECODE_ME_CHECK(b.one(home));
92  }
93  return ES_OK;
94  }
95 
96  template<class View0, class View1, class CtrlView, ReifyMode rm>
97  Actor*
99  return new (home) ReEq<View0,View1,CtrlView,rm>(home,*this);
100  }
101 
102  template<class View0, class View1, class CtrlView, ReifyMode rm>
103  ExecStatus
105  const ModEventDelta&) {
106  if (b.one()) {
107  if (rm == RM_PMI)
108  return home.ES_SUBSUMED(*this);
109  GECODE_REWRITE(*this,(Eq<View0,View1>::post(home(*this),x0,x1)));
110  }
111  if (b.zero()) {
112  if (rm == RM_IMP)
113  return home.ES_SUBSUMED(*this);
114  GECODE_REWRITE(*this,(Distinct<View0,View1>::post(home(*this),x0,x1)));
115  }
116 
117  if (x0.assigned() && x1.assigned()) {
118  // directly test x0==x1
119  GlbRanges<View0> x0lb(x0);
120  GlbRanges<View1> x1lb(x1);
121  bool x0eqx1 = true;
122  for (; x0lb() && x1lb(); ++x0lb, ++x1lb) {
123  if (x0lb.min() != x1lb.min() ||
124  x0lb.max() != x1lb.max()) {
125  x0eqx1 = false;
126  break;
127  }
128  }
129  if (x0eqx1 && !x0lb() && !x1lb()) {
130  if (rm != RM_IMP)
131  GECODE_ME_CHECK(b.one_none(home));
132  return home.ES_SUBSUMED(*this);
133  } else {
134  if (rm != RM_PMI)
135  GECODE_ME_CHECK(b.zero_none(home));
136  return home.ES_SUBSUMED(*this);
137  }
138  }
139 
140  // check whether cardinalities still allow equality
141  if (x0.cardMin() > x1.cardMax() ||
142  x1.cardMin() > x0.cardMax()) {
143  if (rm != RM_PMI)
144  GECODE_ME_CHECK(b.zero_none(home));
145  return home.ES_SUBSUMED(*this);
146  }
147 
148  // check glb(x0) subset lub(x1)
149  GlbRanges<View0> x0lb(x0);
150  LubRanges<View1> x1ub(x1);
152  if ( diff1() ) {
153  if (rm != RM_PMI)
154  GECODE_ME_CHECK(b.zero_none(home));
155  return home.ES_SUBSUMED(*this);
156  }
157 
158  // check glb(x1) subset lub(x0)
159  GlbRanges<View1> x1lb(x1);
160  LubRanges<View0> x0ub(x0);
162  if ( diff2() ) {
163  if (rm != RM_PMI)
164  GECODE_ME_CHECK(b.zero_none(home));
165  return home.ES_SUBSUMED(*this);
166  }
167 
168  return ES_FIX;
169  }
170 
171 }}}
172 
173 // STATISTICS: set-prop
@ RM_PMI
Inverse implication for reification.
Definition: int.hh:869
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3563
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: re-eq.hpp:104
ReEq(Space &home, ReEq &)
Constructor for cloning p.
Definition: re-eq.hpp:53
View1 x1
Definition: rel.hh:177
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: re-eq.hpp:76
@ RM_IMP
Implication for reification.
Definition: int.hh:862
@ LO
Cheap.
Definition: core.hpp:513
Propagator for set equality
Definition: rel.hh:150
CtrlView b
Definition: rel.hh:178
Computation spaces.
Definition: core.hpp:1742
Base-class for both propagators and branchers.
Definition: core.hpp:628
Gecode toplevel namespace
Base-class for propagators.
Definition: core.hpp:1064
int max(void) const
Return largest value of range.
Home class for posting propagators
Definition: core.hpp:856
bool same(VX, VY)
Test whether two views are in fact the same.
Definition: common.hpp:57
virtual void reschedule(Space &home)
Schedule function.
Definition: re-eq.hpp:68
Range iterator for computing set difference.
Definition: ranges-diff.hpp:43
Reified equality propagator
Definition: rel.hh:174
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
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: re-eq.hpp:98
int min(void) const
Return smallest value of range.
static PropCost ternary(PropCost::Mod m)
Three variables for modifier pcm.
Definition: core.hpp:4805
View0 x0
Definition: rel.hh:176
Propagation cost.
Definition: core.hpp:486
Propagator for negated equality
Definition: rel.hh:268
static ExecStatus post(Home home, View0 x, View1 y, CtrlView b)
Post propagator for .
Definition: re-eq.hpp:86
const Gecode::PropCond PC_INT_VAL
Propagate when a view becomes assigned (single value)
Definition: var-type.hpp:82
@ ES_FIX
Propagation has computed fixpoint.
Definition: core.hpp:477
Range iterator for the least upper bound.
Definition: var-imp.hpp:317
#define forceinline
Definition: config.hpp:185
const Gecode::PropCond PC_SET_ANY
Propagate when any bound or the cardinality of a view changes.
Definition: var-type.hpp:248
#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
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function (defined as PC_TERNARY_LO)
Definition: re-eq.hpp:62
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
#define GECODE_REWRITE(prop, post)
Rewrite propagator by executing post function.
Definition: macros.hpp:116
@ ES_OK
Execution is okay.
Definition: core.hpp:476
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:232
ExecStatus
Definition: core.hpp:472