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relax.hh
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33 
34 #ifndef __GECODE_SEARCH_RELAX_HH__
35 #define __GECODE_SEARCH_RELAX_HH__
36 
37 #include <gecode/kernel.hh>
38 #include <gecode/search.hh>
39 
40 namespace Gecode { namespace Search {
41 
43  template<class VarArgs, class Post>
44  forceinline void
45  relax(Home home, const VarArgs& x, const VarArgs& sx, Rnd r,
46  double p, Post& post);
47 
48 
49  template<class VarArgs, class Post>
50  forceinline void
51  relax(Home home, const VarArgs& x, const VarArgs& sx, Rnd r,
52  double p, Post& post) {
53  if (home.failed())
54  return;
55  Region reg;
56  // Which variables to assign
57  Support::BitSet<Region> ax(reg, static_cast<unsigned int>(x.size()));
58  // Select randomly with probability p to relax value
59  for (int i=0; i<x.size(); i++)
60  if (r(UINT_MAX) >=
61  static_cast<unsigned int>(p * static_cast<double>(UINT_MAX)))
62  ax.set(static_cast<unsigned int>(i));
63  if (ax.all())
64  // Choose one variable uniformly and unset it
65  ax.clear(r(static_cast<unsigned int>(x.size())));
67  if (post(home, x[i.val()], sx[i.val()]) != ES_OK) {
68  home.failed();
69  return;
70  }
71  }
72 
73 }}
74 
75 #endif
76 
77 // STATISTICS: search-other
Post propagator for SetVar x
Definition: set.hh:767
void set(unsigned int i)
Set bit i.
Value iterator for values in a bitset.
bool all(void) const
Test whether all bits are set.
Gecode toplevel namespace
void clear(unsigned int i)
Clear bit i.
Home class for posting propagators
Definition: core.hpp:856
Handle to region.
Definition: region.hpp:55
Post propagator for SetVar SetOpType SetVar SetRelType r
Definition: set.hh:767
void relax(Home home, const VarArgs &x, const VarArgs &sx, Rnd r, double p, Post &post)
Relax variables in x from solution sx with probability p.
Definition: relax.hh:51
TFE post(PropagatorGroup g)
Only post functions (but not propagators) from g are considered.
Definition: filter.cpp:138
Random number generator.
Definition: rnd.hpp:42
bool failed(void) const
Check whether corresponding space is failed.
Definition: core.hpp:4048
#define forceinline
Definition: config.hpp:185
Gecode::IntArgs i({1, 2, 3, 4})
@ ES_OK
Execution is okay.
Definition: core.hpp:476
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:232