Edit: /usr/include/boost/graph/hawick_circuits.hpp (14593B)
// Copyright Louis Dionne 2013
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy
// at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_GRAPH_HAWICK_CIRCUITS_HPP
#define BOOST_GRAPH_HAWICK_CIRCUITS_HPP
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include // for boost::tie
#include
#include
#include
#include // for std::pair
#include
namespace boost
{
namespace hawick_circuits_detail
{
//! @internal Functor returning all the vertices adjacent to a vertex.
struct get_all_adjacent_vertices
{
template < typename Sig > struct result;
template < typename This, typename Vertex, typename Graph >
struct result< This(Vertex, Graph) >
{
private:
typedef typename remove_reference< Graph >::type RawGraph;
typedef graph_traits< RawGraph > Traits;
typedef typename Traits::adjacency_iterator AdjacencyIterator;
public:
typedef std::pair< AdjacencyIterator, AdjacencyIterator > type;
};
template < typename Vertex, typename Graph >
typename result< get_all_adjacent_vertices(
BOOST_FWD_REF(Vertex), BOOST_FWD_REF(Graph)) >::type
operator()(BOOST_FWD_REF(Vertex) v, BOOST_FWD_REF(Graph) g) const
{
return adjacent_vertices(
boost::forward< Vertex >(v), boost::forward< Graph >(g));
}
};
//! @internal Functor returning a set of the vertices adjacent to a vertex.
struct get_unique_adjacent_vertices
{
template < typename Sig > struct result;
template < typename This, typename Vertex, typename Graph >
struct result< This(Vertex, Graph) >
{
typedef std::set< typename remove_reference< Vertex >::type > type;
};
template < typename Vertex, typename Graph >
typename result< get_unique_adjacent_vertices(
Vertex, Graph const&) >::type
operator()(Vertex v, Graph const& g) const
{
typedef typename result< get_unique_adjacent_vertices(
Vertex, Graph const&) >::type Set;
return Set(
adjacent_vertices(v, g).first, adjacent_vertices(v, g).second);
}
};
//! @internal
//! Return whether a container contains a given value.
//! This is not meant as a general purpose membership testing function; it
//! would have to be more clever about possible optimizations.
template < typename Container, typename Value >
bool contains(Container const& c, Value const& v)
{
return std::find(boost::begin(c), boost::end(c), v) != boost::end(c);
}
/*!
* @internal
* Algorithm finding all the cycles starting from a given vertex.
*
* The search is only done in the subgraph induced by the starting vertex
* and the vertices with an index higher than the starting vertex.
*/
template < typename Graph, typename Visitor, typename VertexIndexMap,
typename Stack, typename ClosedMatrix, typename GetAdjacentVertices >
struct hawick_circuits_from
{
private:
typedef graph_traits< Graph > Traits;
typedef typename Traits::vertex_descriptor Vertex;
typedef typename Traits::edge_descriptor Edge;
typedef typename Traits::vertices_size_type VerticesSize;
typedef
typename property_traits< VertexIndexMap >::value_type VertexIndex;
typedef typename result_of< GetAdjacentVertices(
Vertex, Graph const&) >::type AdjacentVertices;
typedef typename range_iterator< AdjacentVertices const >::type
AdjacencyIterator;
// The one_bit_color_map starts all white, i.e. not blocked.
// Since we make that assumption (I looked at the implementation, but
// I can't find anything that documents this behavior), we're gonna
// assert it in the constructor.
typedef one_bit_color_map< VertexIndexMap > BlockedMap;
typedef typename property_traits< BlockedMap >::value_type BlockedColor;
static BlockedColor blocked_false_color()
{
return color_traits< BlockedColor >::white();
}
static BlockedColor blocked_true_color()
{
return color_traits< BlockedColor >::black();
}
// This is used by the constructor to secure the assumption
// documented above.
bool blocked_map_starts_all_unblocked() const
{
BOOST_FOREACH (Vertex v, vertices(graph_))
if (is_blocked(v))
return false;
return true;
}
// This is only used in the constructor to make sure the optimization of
// sharing data structures between iterations does not break the code.
bool all_closed_rows_are_empty() const
{
BOOST_FOREACH (typename ClosedMatrix::reference row, closed_)
if (!row.empty())
return false;
return true;
}
public:
hawick_circuits_from(Graph const& graph, Visitor& visitor,
VertexIndexMap const& vim, Stack& stack, ClosedMatrix& closed,
VerticesSize n_vertices)
: graph_(graph)
, visitor_(visitor)
, vim_(vim)
, stack_(stack)
, closed_(closed)
, blocked_(n_vertices, vim_)
{
BOOST_ASSERT(blocked_map_starts_all_unblocked());
// Since sharing the data structures between iterations is
// just an optimization, it must always be equivalent to
// constructing new ones in this constructor.
BOOST_ASSERT(stack_.empty());
BOOST_ASSERT(closed_.size() == n_vertices);
BOOST_ASSERT(all_closed_rows_are_empty());
}
private:
//! @internal Return the index of a given vertex.
VertexIndex index_of(Vertex v) const { return get(vim_, v); }
//! @internal Return whether a vertex `v` is closed to a vertex `u`.
bool is_closed_to(Vertex u, Vertex v) const
{
typedef typename ClosedMatrix::const_reference VertexList;
VertexList closed_to_u = closed_[index_of(u)];
return contains(closed_to_u, v);
}
//! @internal Close a vertex `v` to a vertex `u`.
void close_to(Vertex u, Vertex v)
{
BOOST_ASSERT(!is_closed_to(u, v));
closed_[index_of(u)].push_back(v);
}
//! @internal Return whether a given vertex is blocked.
bool is_blocked(Vertex v) const
{
return get(blocked_, v) == blocked_true_color();
}
//! @internal Block a given vertex.
void block(Vertex v) { put(blocked_, v, blocked_true_color()); }
//! @internal Unblock a given vertex.
void unblock(Vertex u)
{
typedef typename ClosedMatrix::reference VertexList;
put(blocked_, u, blocked_false_color());
VertexList closed_to_u = closed_[index_of(u)];
while (!closed_to_u.empty())
{
Vertex const w = closed_to_u.back();
closed_to_u.pop_back();
if (is_blocked(w))
unblock(w);
}
BOOST_ASSERT(closed_to_u.empty());
}
//! @internal Main procedure as described in the paper.
bool circuit(Vertex start, Vertex v)
{
bool found_circuit = false;
stack_.push_back(v);
block(v);
// Cache some values that are used more than once in the function.
VertexIndex const index_of_start = index_of(start);
AdjacentVertices const adj_vertices
= GetAdjacentVertices()(v, graph_);
AdjacencyIterator const w_end = boost::end(adj_vertices);
for (AdjacencyIterator w_it = boost::begin(adj_vertices);
w_it != w_end; ++w_it)
{
Vertex const w = *w_it;
// Since we're only looking in the subgraph induced by `start`
// and the vertices with an index higher than `start`, we skip
// any vertex that does not satisfy that.
if (index_of(w) < index_of_start)
continue;
// If the last vertex is equal to `start`, we have a circuit.
else if (w == start)
{
// const_cast to ensure the visitor does not modify the
// stack
visitor_.cycle(const_cast< Stack const& >(stack_), graph_);
found_circuit = true;
}
// If `w` is not blocked, we continue searching further down the
// same path for a cycle with `w` in it.
else if (!is_blocked(w) && circuit(start, w))
found_circuit = true;
}
if (found_circuit)
unblock(v);
else
for (AdjacencyIterator w_it = boost::begin(adj_vertices);
w_it != w_end; ++w_it)
{
Vertex const w = *w_it;
// Like above, we skip vertices that are not in the subgraph
// we're considering.
if (index_of(w) < index_of_start)
continue;
// If `v` is not closed to `w`, we make it so.
if (!is_closed_to(w, v))
close_to(w, v);
}
BOOST_ASSERT(v == stack_.back());
stack_.pop_back();
return found_circuit;
}
public:
void operator()(Vertex start) { circuit(start, start); }
private:
Graph const& graph_;
Visitor& visitor_;
VertexIndexMap const& vim_;
Stack& stack_;
ClosedMatrix& closed_;
BlockedMap blocked_;
};
template < typename GetAdjacentVertices, typename Graph, typename Visitor,
typename VertexIndexMap >
void call_hawick_circuits(Graph const& graph,
Visitor /* by value */ visitor, VertexIndexMap const& vertex_index_map)
{
typedef graph_traits< Graph > Traits;
typedef typename Traits::vertex_descriptor Vertex;
typedef typename Traits::vertices_size_type VerticesSize;
typedef typename Traits::vertex_iterator VertexIterator;
typedef std::vector< Vertex > Stack;
typedef std::vector< std::vector< Vertex > > ClosedMatrix;
typedef hawick_circuits_from< Graph, Visitor, VertexIndexMap, Stack,
ClosedMatrix, GetAdjacentVertices >
SubAlgorithm;
VerticesSize const n_vertices = num_vertices(graph);
Stack stack;
stack.reserve(n_vertices);
ClosedMatrix closed(n_vertices);
VertexIterator start, last;
for (boost::tie(start, last) = vertices(graph); start != last; ++start)
{
// Note1: The sub algorithm may NOT be reused once it has been
// called.
// Note2: We reuse the Stack and the ClosedMatrix (after clearing
// them) in each iteration to avoid redundant destruction and
// construction. It would be strictly equivalent to have these as
// member variables of the sub algorithm.
SubAlgorithm sub_algo(
graph, visitor, vertex_index_map, stack, closed, n_vertices);
sub_algo(*start);
stack.clear();
typename ClosedMatrix::iterator row, last_row = closed.end();
for (row = closed.begin(); row != last_row; ++row)
row->clear();
}
}
template < typename GetAdjacentVertices, typename Graph, typename Visitor >
void call_hawick_circuits(
Graph const& graph, BOOST_FWD_REF(Visitor) visitor)
{
call_hawick_circuits< GetAdjacentVertices >(graph,
boost::forward< Visitor >(visitor), get(vertex_index, graph));
}
} // end namespace hawick_circuits_detail
//! Enumerate all the elementary circuits in a directed multigraph.
template < typename Graph, typename Visitor, typename VertexIndexMap >
void hawick_circuits(BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor,
BOOST_FWD_REF(VertexIndexMap) vertex_index_map)
{
hawick_circuits_detail::call_hawick_circuits<
hawick_circuits_detail::get_all_adjacent_vertices >(
boost::forward< Graph >(graph), boost::forward< Visitor >(visitor),
boost::forward< VertexIndexMap >(vertex_index_map));
}
template < typename Graph, typename Visitor >
void hawick_circuits(BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor)
{
hawick_circuits_detail::call_hawick_circuits<
hawick_circuits_detail::get_all_adjacent_vertices >(
boost::forward< Graph >(graph), boost::forward< Visitor >(visitor));
}
/*!
* Same as `boost::hawick_circuits`, but duplicate circuits caused by parallel
* edges will not be considered. Each circuit will be considered only once.
*/
template < typename Graph, typename Visitor, typename VertexIndexMap >
void hawick_unique_circuits(BOOST_FWD_REF(Graph) graph,
BOOST_FWD_REF(Visitor) visitor,
BOOST_FWD_REF(VertexIndexMap) vertex_index_map)
{
hawick_circuits_detail::call_hawick_circuits<
hawick_circuits_detail::get_unique_adjacent_vertices >(
boost::forward< Graph >(graph), boost::forward< Visitor >(visitor),
boost::forward< VertexIndexMap >(vertex_index_map));
}
template < typename Graph, typename Visitor >
void hawick_unique_circuits(
BOOST_FWD_REF(Graph) graph, BOOST_FWD_REF(Visitor) visitor)
{
hawick_circuits_detail::call_hawick_circuits<
hawick_circuits_detail::get_unique_adjacent_vertices >(
boost::forward< Graph >(graph), boost::forward< Visitor >(visitor));
}
} // end namespace boost
#endif // !BOOST_GRAPH_HAWICK_CIRCUITS_HPP