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int-lq.hpp
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3  * Main authors:
4  * Christian Schulte <schulte@gecode.org>
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6  * Copyright:
7  * Christian Schulte, 2011
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10  * $Date: 2012-09-07 17:31:22 +0200 (Fri, 07 Sep 2012) $ by $Author: schulte $
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37 
38 #include <gecode/int/rel.hh>
39 #include <gecode/int/distinct.hh>
40 
41 namespace Gecode { namespace Int { namespace NValues {
42 
43  template<class VY>
46  : IntBase<VY>(home,vs,x,y) {
47  home.notice(*this, AP_WEAKLY);
48  }
49 
50  template<class VY>
51  inline ExecStatus
53  if (x.size() == 0) {
54  GECODE_ME_CHECK(y.eq(home,0));
55  return ES_OK;
56  }
57 
58  x.unique(home);
59 
60  GECODE_ME_CHECK(y.gq(home,1));
61 
62  if (x.size() == 1)
63  return ES_OK;
64 
65  if (y.max() == 1) {
66  assert(y.assigned());
67  return Rel::NaryEqDom<IntView>::post(home,x);
68  }
69 
70  if (y.min() >= x.size())
71  return ES_OK;
72 
73  // Eliminate assigned views and store them into the value set
74  ValSet vs;
75  int n = x.size();
76  for (int i=n; i--; )
77  if (x[i].assigned()) {
78  vs.add(home, x[i].val());
79  x[i] = x[--n];
80  }
81 
82  GECODE_ME_CHECK(y.gq(home,vs.size()));
83 
84  if (n == 0) {
85  assert(y.min() >= vs.size());
86  return ES_OK;
87  }
88 
89  x.size(n);
90 
91  (void) new (home) LqInt<VY>(home, vs, x, y);
92  return ES_OK;
93  }
94 
95  template<class VY>
97  LqInt<VY>::LqInt(Space& home, bool share, LqInt<VY>& p)
98  : IntBase<VY>(home, share, p) {}
99 
100  template<class VY>
101  Propagator*
102  LqInt<VY>::copy(Space& home, bool share) {
103  return new (home) LqInt<VY>(home, share, *this);
104  }
105 
106  template<class VY>
107  forceinline size_t
109  home.ignore(*this, AP_WEAKLY);
110  (void) IntBase<VY>::dispose(home);
111  return sizeof(*this);
112  }
113 
114  template<class VY>
115  ExecStatus
117  // Add assigned views to value set
118  if (IntView::me(med) == ME_INT_VAL)
119  add(home);
120 
121  GECODE_ME_CHECK(y.gq(home, vs.size()));
122 
123  if (x.size() == 0)
124  return home.ES_SUBSUMED(*this);
125 
126  // All values must be in the value set
127  if (y.max() == vs.size())
128  return all_in_valset(home);
129 
130  if (x.size() + vs.size() <= y.min())
131  return home.ES_SUBSUMED(*this);
132 
133  // Compute positions of disjoint views
134  Region r(home);
135  int* dis; int n_dis;
136  disjoint(home,r,dis,n_dis);
137 
138  // Some views might have been eliminated as they are subsumed
139  if (x.size() == 0)
140  return home.ES_SUBSUMED(*this);
141 
142  // No lower bound pruning possible
143  if (n_dis == 0)
144  return ES_NOFIX;
145 
146  // Do lower bound-based pruning
147  GECODE_ES_CHECK(prune_lower(home,dis,n_dis));
148 
149  return ES_NOFIX;
150  }
151 
152 }}}
153 
154 // STATISTICS: int-prop
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: int-lq.hpp:116
int size(void) const
Return size (number of values)
Definition: val-set.hpp:85
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:2973
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: int-lq.hpp:108
LqInt(Home home, ValSet &vs, ViewArray< IntView > &x, VY y)
Constructor for posting.
Definition: int-lq.hpp:45
Base-class for propagators.
Definition: core.hpp:755
Handle to region.
Definition: region.hpp:61
void unique(const Space &home)
Remove all duplicate views from array (changes element order)
Definition: array.hpp:1498
Computation spaces.
Definition: core.hpp:1362
#define GECODE_ES_CHECK(es)
Check whether execution status es is failed or subsumed, and forward failure or subsumption.
Definition: macros.hpp:84
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:236
Gecode::IntArgs i(4, 1, 2, 3, 4)
int n
Number of negative literals for node type.
Definition: bool-expr.cpp:238
NNF * r
Right subtree.
Definition: bool-expr.cpp:246
const Gecode::ModEvent ME_INT_VAL
Domain operation has resulted in a value (assigned variable)
Definition: var-type.hpp:56
virtual Propagator * copy(Space &home, bool share)
Copy propagator during cloning.
Definition: int-lq.hpp:102
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:45
void notice(Actor &a, ActorProperty p, bool duplicate=false)
Notice actor property.
Definition: core.hpp:2849
Less or equal to number of values propagator for integer views.
Definition: nvalues.hh:225
Node * x
Pointer to corresponding Boolean expression node.
Definition: bool-expr.cpp:253
void ignore(Actor &a, ActorProperty p, bool duplicate=false)
Ignore actor property.
Definition: core.cpp:169
ExecStatus
Definition: core.hpp:523
bool assigned(View x, int v)
Whether x is assigned to value v.
Definition: single.hpp:47
static ModEvent me(const ModEventDelta &med)
Return modification event for view type in med.
bool disjoint(I &i, J &j)
Check whether range iterators i and j are disjoint.
#define forceinline
Definition: config.hpp:132
Execution is okay.
Definition: core.hpp:527
Propagation has not computed fixpoint.
Definition: core.hpp:526
Class for storing values of already assigned views.
Definition: val-set.hh:48
int size(void) const
Return size of array (number of elements)
Definition: array.hpp:1215
Gecode toplevel namespace
static ExecStatus post(Home home, ViewArray< View > &x)
Post domain consistent propagator .
Definition: eq.hpp:214
Number of values propagator for integer views base class.
Definition: nvalues.hh:136
int ModEventDelta
Modification event deltas.
Definition: core.hpp:173
Home class for posting propagators
Definition: core.hpp:717
void add(Space &home, int v)
Add value v to value set.
Definition: val-set.hpp:49
static ExecStatus post(Home home, ViewArray< IntView > &x, VY y)
Post propagator for .
Definition: int-lq.hpp:52