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nq.hpp
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1 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
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3  * Main authors:
4  * Christian Schulte <schulte@gecode.org>
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7  * Christian Schulte, 2004
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33 
34 #include <algorithm>
35 
36 namespace Gecode { namespace Int { namespace Rel {
37 
38  /*
39  * Disequality
40  *
41  */
42  template<class V0, class V1>
44  Nq<V0,V1>::Nq(Home home, V0 x0, V1 x1)
45  : MixBinaryPropagator<V0,PC_INT_VAL,V1,PC_INT_VAL>(home,x0,x1) {}
46 
47  template<class V0, class V1>
49  Nq<V0,V1>::post(Home home, V0 x0, V1 x1){
50  if (x0.assigned()) {
51  GECODE_ME_CHECK(x1.nq(home,x0.val()));
52  } else if (x1.assigned()) {
53  GECODE_ME_CHECK(x0.nq(home,x1.val()));
54  } else if (x0 == x1) {
55  return ES_FAILED;
56  } else {
57  (void) new (home) Nq<V0,V1>(home,x0,x1);
58  }
59  return ES_OK;
60  }
61 
62  template<class V0, class V1>
65  : MixBinaryPropagator<V0,PC_INT_VAL,V1,PC_INT_VAL>(home,p) {}
66 
67  template<class V0, class V1>
68  Actor*
70  return new (home) Nq<V0,V1>(home,*this);
71  }
72 
73  template<class V0, class V1>
74  PropCost
75  Nq<V0,V1>::cost(const Space&, const ModEventDelta&) const {
77  }
78 
79  template<class V0, class V1>
82  if (x0.assigned()) {
83  GECODE_ME_CHECK(x1.nq(home,x0.val()));
84  } else {
85  GECODE_ME_CHECK(x0.nq(home,x1.val()));
86  }
87  return home.ES_SUBSUMED(*this);
88  }
89 
90 
91  /*
92  * Nary disequality propagator
93  */
94  template<class View>
97  : NaryPropagator<View,PC_INT_VAL>(home,x) {}
98 
99  template<class View>
100  PropCost
101  NaryNq<View>::cost(const Space&, const ModEventDelta&) const {
102  return PropCost::linear(PropCost::LO,x.size());
103  }
104 
105  template<class View>
108  : NaryPropagator<View,PC_INT_VAL>(home,p) {}
109 
110  template<class View>
111  Actor*
113  return new (home) NaryNq<View>(home,*this);
114  }
115 
116  template<class View>
117  inline ExecStatus
119  x.unique();
120  // Try to find an assigned view
121  int n = x.size();
122  if (n <= 1)
123  return ES_FAILED;
124  for (int i=n; i--; )
125  if (x[i].assigned()) {
126  std::swap(x[0],x[i]);
127  break;
128  }
129  if (x[0].assigned()) {
130  int v = x[0].val();
131  // Eliminate all equal views and possibly find disequal view
132  for (int i=n-1; i>0; i--)
133  if (!x[i].in(v)) {
134  return ES_OK;
135  } else if (x[i].assigned()) {
136  assert(x[i].val() == v);
137  x[i]=x[--n];
138  }
139  x.size(n);
140  }
141  if (n == 1)
142  return ES_FAILED;
143  if (n == 2)
144  return Nq<View,View>::post(home,x[0],x[1]);
145  (void) new (home) NaryNq(home,x);
146  return ES_OK;
147  }
148 
149  template<class View>
150  forceinline size_t
153  return sizeof(*this);
154  }
155 
156  template<class View>
157  ExecStatus
159  // Make sure that x[0] is assigned
160  if (!x[0].assigned()) {
161  // Note that there is at least one assigned view
162  for (int i=1; true; i++)
163  if (x[i].assigned()) {
164  std::swap(x[0],x[i]);
165  break;
166  }
167  }
168  int v = x[0].val();
169  int n = x.size();
170  for (int i=n-1; i>0; i--)
171  if (!x[i].in(v)) {
172  x.size(n);
173  return home.ES_SUBSUMED(*this);
174  } else if (x[i].assigned()) {
175  assert(x[i].val() == v);
176  x[i] = x[--n];
177  }
178  x.size(n);
179  if (n == 1)
180  return ES_FAILED;
181  if (n == 2) {
182  GECODE_ME_CHECK(x[1].nq(home,v));
183  return home.ES_SUBSUMED(*this);
184  }
185  return ES_FIX;
186  }
187 
188 
189 
190 }}}
191 
192 // STATISTICS: int-prop
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: nq.hpp:81
Post propagator for SetVar x
Definition: set.hh:767
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3563
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: nq.hpp:158
static ExecStatus post(Home home, V0 x0, V1 x1)
Post propagator .
Definition: nq.hpp:49
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function.
Definition: nq.hpp:101
bool assigned(View x, int v)
Whether x is assigned to value v.
Definition: single.hpp:43
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: nq.hpp:151
Cheap.
Definition: core.hpp:513
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
Binary disequality propagator.
Definition: rel.hh:460
Gecode toplevel namespace
Mixed binary propagator.
Definition: pattern.hpp:204
Home class for posting propagators
Definition: core.hpp:856
Nary disequality propagator.
Definition: rel.hh:318
Nq(Space &home, Nq< V0, V1 > &p)
Constructor for cloning p.
Definition: nq.hpp:64
static PropCost unary(PropCost::Mod m)
Single variable for modifier pcm.
Definition: core.hpp:4813
n-ary propagator
Definition: pattern.hpp:142
IntRelType swap(IntRelType irt)
Return swapped relation type of irt.
Definition: irt.hpp:37
static ExecStatus post(Home home, ViewArray< View > &x)
Post propagator .
Definition: nq.hpp:118
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: nq.hpp:112
Propagation cost.
Definition: core.hpp:486
const int v[7]
Definition: distinct.cpp:259
const Gecode::PropCond PC_INT_VAL
Propagate when a view becomes assigned (single value)
Definition: var-type.hpp:82
Propagation has computed fixpoint.
Definition: core.hpp:477
#define forceinline
Definition: config.hpp:185
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function (defined as low unary)
Definition: nq.hpp:75
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:52
View arrays.
Definition: array.hpp:253
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: nq.hpp:69
int n
Number of negative literals for node type.
Definition: bool-expr.cpp:234
Execution has resulted in failure.
Definition: core.hpp:474
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
NaryNq(Home home, ViewArray< View > &x)
Constructor for posting.
Definition: nq.hpp:96
Gecode::IntArgs i({1, 2, 3, 4})
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