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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
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42 
43 namespace Gecode { namespace Set { namespace Rel {
44 
45  template<class View0, class View1, class CtrlView, ReifyMode rm>
47  ReEq<View0,View1,CtrlView,rm>::ReEq(Home home, View0 y0, View1 y1,
48  CtrlView y2)
49  : Propagator(home), x0(y0), x1(y1), b(y2) {
50  b.subscribe(home,*this, Gecode::Int::PC_INT_VAL);
51  x0.subscribe(home,*this, PC_SET_ANY);
52  x1.subscribe(home,*this, PC_SET_ANY);
53  }
54 
55  template<class View0, class View1, class CtrlView, ReifyMode rm>
58  : Propagator(home,p) {
59  x0.update(home,p.x0);
60  x1.update(home,p.x1);
61  b.update(home,p.b);
62  }
63 
64  template<class View0, class View1, class CtrlView, ReifyMode rm>
65  PropCost
68  }
69 
70  template<class View0, class View1, class CtrlView, ReifyMode rm>
71  void
73  b.reschedule(home,*this, Gecode::Int::PC_INT_VAL);
74  x0.reschedule(home,*this, PC_SET_ANY);
75  x1.reschedule(home,*this, PC_SET_ANY);
76  }
77 
78  template<class View0, class View1, class CtrlView, ReifyMode rm>
79  forceinline size_t
81  b.cancel(home,*this, Gecode::Int::PC_INT_VAL);
82  x0.cancel(home,*this, PC_SET_ANY);
83  x1.cancel(home,*this, PC_SET_ANY);
84  (void) Propagator::dispose(home);
85  return sizeof(*this);
86  }
87 
88  template<class View0, class View1, class CtrlView, ReifyMode rm>
91  CtrlView b) {
92  if (!same(x0,x1)) {
93  (void) new (home) ReEq<View0,View1,CtrlView,rm>(home,x0,x1,b);
94  } else if (rm != RM_IMP) {
95  GECODE_ME_CHECK(b.one(home));
96  }
97  return ES_OK;
98  }
99 
100  template<class View0, class View1, class CtrlView, ReifyMode rm>
101  Actor*
103  return new (home) ReEq<View0,View1,CtrlView,rm>(home,*this);
104  }
105 
106  template<class View0, class View1, class CtrlView, ReifyMode rm>
107  ExecStatus
109  const ModEventDelta&) {
110  if (b.one()) {
111  if (rm == RM_PMI)
112  return home.ES_SUBSUMED(*this);
113  GECODE_REWRITE(*this,(Eq<View0,View1>::post(home(*this),x0,x1)));
114  }
115  if (b.zero()) {
116  if (rm == RM_IMP)
117  return home.ES_SUBSUMED(*this);
118  GECODE_REWRITE(*this,(Distinct<View0,View1>::post(home(*this),x0,x1)));
119  }
120 
121  if (x0.assigned() && x1.assigned()) {
122  // directly test x0==x1
123  GlbRanges<View0> x0lb(x0);
124  GlbRanges<View1> x1lb(x1);
125  bool x0eqx1 = true;
126  for (; x0lb() && x1lb(); ++x0lb, ++x1lb) {
127  if (x0lb.min() != x1lb.min() ||
128  x0lb.max() != x1lb.max()) {
129  x0eqx1 = false;
130  break;
131  }
132  }
133  if (x0eqx1 && !x0lb() && !x1lb()) {
134  if (rm != RM_IMP)
135  GECODE_ME_CHECK(b.one_none(home));
136  return home.ES_SUBSUMED(*this);
137  } else {
138  if (rm != RM_PMI)
139  GECODE_ME_CHECK(b.zero_none(home));
140  return home.ES_SUBSUMED(*this);
141  }
142  }
143 
144  // check whether cardinalities still allow equality
145  if (x0.cardMin() > x1.cardMax() ||
146  x1.cardMin() > x0.cardMax()) {
147  if (rm != RM_PMI)
148  GECODE_ME_CHECK(b.zero_none(home));
149  return home.ES_SUBSUMED(*this);
150  }
151 
152  // check glb(x0) subset lub(x1)
153  GlbRanges<View0> x0lb(x0);
154  LubRanges<View1> x1ub(x1);
156  if ( diff1() ) {
157  if (rm != RM_PMI)
158  GECODE_ME_CHECK(b.zero_none(home));
159  return home.ES_SUBSUMED(*this);
160  }
161 
162  // check glb(x1) subset lub(x0)
163  GlbRanges<View1> x1lb(x1);
164  LubRanges<View0> x0ub(x0);
166  if ( diff2() ) {
167  if (rm != RM_PMI)
168  GECODE_ME_CHECK(b.zero_none(home));
169  return home.ES_SUBSUMED(*this);
170  }
171 
172  return ES_FIX;
173  }
174 
175 }}}
176 
177 // STATISTICS: set-prop
#define GECODE_REWRITE(prop, post)
Rewrite propagator by executing post function.
Definition: macros.hpp:120
Propagator for negated equality
Definition: rel.hh:271
static ExecStatus post(Home home, View0 x, View1 y, CtrlView b)
Post propagator for .
Definition: re-eq.hpp:90
int min(void) const
Return smallest value of range.
Inverse implication for reification.
Definition: int.hh:848
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3433
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: re-eq.hpp:102
Base-class for propagators.
Definition: core.hpp:1016
Range iterator for the greatest lower bound.
Definition: var-imp.hpp:363
#define forceinline
Definition: config.hpp:182
Propagation has computed fixpoint.
Definition: core.hpp:469
Computation spaces.
Definition: core.hpp:1668
Range iterator for the least upper bound.
Definition: var-imp.hpp:321
Base-class for both propagators and branchers.
Definition: core.hpp:620
Reified equality propagator
Definition: rel.hh:178
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:236
bool same(VX, VY)
Test whether two views are in fact the same.
Definition: common.hpp:61
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function (defined as PC_TERNARY_LO)
Definition: re-eq.hpp:66
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:56
const Gecode::PropCond PC_SET_ANY
Propagate when any bound or the cardinality of a view changes.
Definition: var-type.hpp:248
struct Gecode::@585::NNF::@62::@63 b
For binary nodes (and, or, eqv)
ReEq(Space &home, ReEq &)
Constructor for cloning p.
Definition: re-eq.hpp:57
virtual size_t dispose(Space &home)
Delete actor and return its size.
Definition: core.hpp:3172
Propagation cost.
Definition: core.hpp:478
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: re-eq.hpp:80
ExecStatus
Definition: core.hpp:464
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: re-eq.hpp:108
Propagator for set equality
Definition: rel.hh:154
Execution is okay.
Definition: core.hpp:468
int max(void) const
Return largest value of range.
static PropCost ternary(PropCost::Mod m)
Three variables for modifier pcm.
Definition: core.hpp:4652
Gecode toplevel namespace
Implication for reification.
Definition: int.hh:841
Range iterator for computing set difference.
Definition: ranges-diff.hpp:47
int ModEventDelta
Modification event deltas.
Definition: core.hpp:91
virtual void reschedule(Space &home)
Schedule function.
Definition: re-eq.hpp:72
Home class for posting propagators
Definition: core.hpp:846
const Gecode::PropCond PC_INT_VAL
Propagate when a view becomes assigned (single value)
Definition: var-type.hpp:82