relax.hh
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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Christian Schulte <schulte@gecode.org>
*
* Copyright:
* Christian Schulte, 2016
*
* This file is part of Gecode, the generic constraint
* development environment:
* http://www.gecode.org
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#ifndef __GECODE_SEARCH_RELAX_HH__
#define __GECODE_SEARCH_RELAX_HH__
#include <gecode/kernel.hh>
#include <gecode/search.hh>
namespace Gecode { namespace Search {
template<class VarArgs, class Post>
forceinline void
relax(Home home, const VarArgs& x, const VarArgs& sx, Rnd r,
double p, Post& post);
template<class VarArgs, class Post>
forceinline void
relax(Home home, const VarArgs& x, const VarArgs& sx, Rnd r,
double p, Post& post) {
if (home.failed())
return;
Region reg;
// Which variables to assign
Support::BitSet<Region> ax(reg, static_cast<unsigned int>(x.size()));
// Select randomly with probability p to relax value
for (int i=0; i<x.size(); i++)
if (r(UINT_MAX) >=
static_cast<unsigned int>(p * static_cast<double>(UINT_MAX)))
ax.set(static_cast<unsigned int>(i));
if (ax.all())
// Choose one variable uniformly and unset it
ax.clear(r(static_cast<unsigned int>(x.size())));
for (Iter::Values::BitSet<Support::BitSet<Region> > i(ax); i(); ++i)
if (post(home, x[i.val()], sx[i.val()]) != ES_OK) {
home.failed();
return;
}
}
}}
#endif
// STATISTICS: search-other
Gecode::ArgArrayBase::size
int size(void) const
Return size of array (number of elements).
Definition array.hpp:1607
Gecode::Home
Home class for posting propagators
Definition core.hpp:856
Gecode::Home::failed
bool failed(void) const
Check whether corresponding space is failed.
Definition core.hpp:4048
Gecode::Iter::Values::BitSet
Value iterator for values in a bitset.
Definition values-bitset.hpp:42
Gecode::Region
Handle to region.
Definition region.hpp:55
Gecode::Rnd
Random number generator.
Definition rnd.hpp:42
Gecode::Support::BitSetBase::all
bool all(void) const
Test whether all bits are set.
Definition bitset-base.hpp:617
Gecode::Support::BitSetBase::clear
void clear(unsigned int i)
Clear bit i.
Definition bitset-base.hpp:600
Gecode::Support::BitSetBase::set
void set(unsigned int i)
Set bit i.
Definition bitset-base.hpp:595
Gecode::Support::BitSet
Simple bitsets.
Definition bitset.hpp:45
kernel.hh
Gecode::Search
Search engines
Gecode::Search::relax
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
Gecode
Gecode toplevel namespace
Gecode::post
TFE post(PropagatorGroup g)
Only post functions (but not propagators) from g are considered.
Definition filter.cpp:138
Gecode::ES_OK
@ ES_OK
Execution is okay.
Definition core.hpp:476
search.hh
forceinline
#define forceinline
Definition config.hpp:187