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eq.hpp
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4  * Christian Schulte <schulte@gecode.org>
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7  * Christian Schulte, 2004
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37 
38 namespace Gecode { namespace Int { namespace Bool {
39 
40  template<class BVA, class BVB>
42  Eq<BVA,BVB>::Eq(Home home, BVA b0, BVB b1)
43  : BoolBinary<BVA,BVB>(home,b0,b1) {}
44 
45  template<class BVA, class BVB>
47  Eq<BVA,BVB>::Eq(Space& home, bool share, Eq<BVA,BVB>& p)
48  : BoolBinary<BVA,BVB>(home,share,p) {}
49 
50  template<class BVA, class BVB>
52  Eq<BVA,BVB>::Eq(Space& home, bool share, Propagator& p,
53  BVA b0, BVB b1)
54  : BoolBinary<BVA,BVB>(home,share,p,b0,b1) {}
55 
56  template<class BVA, class BVB>
57  Actor*
58  Eq<BVA,BVB>::copy(Space& home, bool share) {
59  return new (home) Eq<BVA,BVB>(home,share,*this);
60  }
61 
62  template<class BVA, class BVB>
63  inline ExecStatus
64  Eq<BVA,BVB>::post(Home home, BVA b0, BVB b1) {
65  switch (bool_test(b0,b1)) {
66  case BT_SAME: return ES_OK;
67  case BT_COMP: return ES_FAILED;
68  case BT_NONE:
69  if (b0.zero()) {
70  GECODE_ME_CHECK(b1.zero(home));
71  } else if (b0.one()) {
72  GECODE_ME_CHECK(b1.one(home));
73  } else if (b1.zero()) {
74  GECODE_ME_CHECK(b0.zero(home));
75  } else if (b1.one()) {
76  GECODE_ME_CHECK(b0.one(home));
77  } else {
78  (void) new (home) Eq<BVA,BVB>(home,b0,b1);
79  }
80  break;
81  default: GECODE_NEVER;
82  }
83  return ES_OK;
84  }
85 
86  template<class BVA, class BVB>
89 #define GECODE_INT_STATUS(S0,S1) \
90  ((BVA::S0<<(1*BVA::BITS))|(BVB::S1<<(0*BVB::BITS)))
91  switch ((x0.status() << (1*BVA::BITS)) | (x1.status() << (0*BVB::BITS))) {
92  case GECODE_INT_STATUS(NONE,NONE):
94  case GECODE_INT_STATUS(NONE,ZERO):
95  GECODE_ME_CHECK(x0.zero_none(home)); break;
96  case GECODE_INT_STATUS(NONE,ONE):
97  GECODE_ME_CHECK(x0.one_none(home)); break;
98  case GECODE_INT_STATUS(ZERO,NONE):
99  GECODE_ME_CHECK(x1.zero_none(home)); break;
100  case GECODE_INT_STATUS(ZERO,ZERO):
101  break;
102  case GECODE_INT_STATUS(ZERO,ONE):
103  return ES_FAILED;
104  case GECODE_INT_STATUS(ONE,NONE):
105  GECODE_ME_CHECK(x1.one_none(home)); break;
106  case GECODE_INT_STATUS(ONE,ZERO):
107  return ES_FAILED;
108  case GECODE_INT_STATUS(ONE,ONE):
109  break;
110  default:
111  GECODE_NEVER;
112  }
113  return home.ES_SUBSUMED(*this);
114 #undef GECODE_INT_STATUS
115  }
116 
117  template<class BV>
120  : NaryPropagator<BV,PC_BOOL_VAL>(home,x) {}
121 
122  template<class BV>
124  NaryEq<BV>::NaryEq(Space& home, bool share, NaryEq<BV>& p)
125  : NaryPropagator<BV,PC_BOOL_VAL>(home,share,p) {}
126 
127  template<class BV>
128  Actor*
129  NaryEq<BV>::copy(Space& home, bool share) {
130  return new (home) NaryEq<BV>(home,share,*this);
131  }
132 
133  template<class BV>
134  inline ExecStatus
136  x.unique(home);
137  int n = x.size();
138  if (n < 2)
139  return ES_OK;
140  if (n == 2)
141  return Eq<BV,BV>::post(home,x[0],x[1]);
142  for (int i=n; i--; )
143  if (x[i].assigned()) {
144  if (x[i].one()) {
145  for (int j=i; j--; )
146  GECODE_ME_CHECK(x[j].one(home));
147  for (int j=i+1; j<n; j++)
148  GECODE_ME_CHECK(x[j].one_none(home));
149  } else {
150  for (int j=i; j--; )
151  GECODE_ME_CHECK(x[j].zero(home));
152  for (int j=i+1; j<n; j++)
153  GECODE_ME_CHECK(x[j].zero_none(home));
154  }
155  return ES_OK;
156  }
157  (void) new (home) NaryEq<BV>(home,x);
158  return ES_OK;
159  }
160 
161  template<class BV>
162  PropCost
163  NaryEq<BV>::cost(const Space&, const ModEventDelta&) const {
165  }
166 
167  template<class BV>
168  ExecStatus
170  int n=x.size();
171  int i=0;
172  while (true) {
173  if (x[i].assigned()) {
174  if (x[i].one()) {
175  for (int j=0; j<i; j++)
176  GECODE_ME_CHECK(x[j].one_none(home));
177  for (int j=i+1; j<n; j++)
178  GECODE_ME_CHECK(x[j].one(home));
179  } else {
180  for (int j=0; j<i; j++)
181  GECODE_ME_CHECK(x[j].zero_none(home));
182  for (int j=i+1; j<n; j++)
183  GECODE_ME_CHECK(x[j].zero(home));
184  }
185  return home.ES_SUBSUMED(*this);
186  }
187  i++;
188  }
189  GECODE_NEVER;
190  return ES_FIX;
191  }
192 
193 }}}
194 
195 // STATISTICS: int-prop
196