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Importing all_cliques, all_cycles algorithms

[SVN r51094]
This commit is contained in:
Andrew Sutton
2009-02-08 14:51:58 +00:00
parent 77d5bf7b80
commit aed5fa9949
4 changed files with 709 additions and 16 deletions

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@@ -0,0 +1,309 @@
// (C) Copyright 2007-2009 Andrew Sutton
//
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0 (See accompanying file
// LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_GRAPH_CLIQUE_HXX
#define BOOST_GRAPH_CLIQUE_HXX
#include <vector>
#include <deque>
#include <boost/graph/graph_concepts.hpp>
#include <boost/concept/detail/concept_def.hpp>
namespace boost {
namespace concepts {
BOOST_concept(CliqueVisitor,(Visitor)(Clique)(Graph))
{
BOOST_CONCEPT_USAGE(CliqueVisitor)
{
vis.clique(k, g);
}
private:
Visitor vis;
Graph g;
Clique k;
};
} /* namespace concepts */
using concepts::CliqueVisitorConcept;
} /* namespace boost */
#include <boost/concept/detail/concept_undef.hpp>
namespace boost
{
// The algorithm implemented in this paper is based on the so-called
// Algorithm 457, published as:
//
// @article{362367,
// author = {Coen Bron and Joep Kerbosch},
// title = {Algorithm 457: finding all cliques of an undirected graph},
// journal = {Communications of the ACM},
// volume = {16},
// number = {9},
// year = {1973},
// issn = {0001-0782},
// pages = {575--577},
// doi = {http://doi.acm.org/10.1145/362342.362367},
// publisher = {ACM Press},
// address = {New York, NY, USA},
// }
//
// Sort of. This implementation is adapted from the 1st version of the
// algorithm and does not implement the candidate selection optimization
// described as published - it could, it just doesn't yet.
//
// The algorithm is given as proportional to (3.14)^(n/3) power. This is
// not the same as O(...), but based on time measures and approximation.
//
// Unfortunately, this implementation may be less efficient on non-
// AdjacencyMatrix modeled graphs due to the non-constant implementation
// of the edge(u,v,g) functions.
//
// TODO: It might be worthwhile to provide functionality for passing
// a connectivity matrix to improve the efficiency of those lookups
// when needed. This could simply be passed as a BooleanMatrix
// s.t. edge(u,v,B) returns true or false. This could easily be
// abstracted for adjacency matricies.
//
// The following paper is interesting for a number of reasons. First,
// it lists a number of other such algorithms and second, it describes
// a new algorithm (that does not appear to require the edge(u,v,g)
// function and appears fairly efficient. It is probably worth investigating.
//
// @article{DBLP:journals/tcs/TomitaTT06,
// author = {Etsuji Tomita and Akira Tanaka and Haruhisa Takahashi},
// title = {The worst-case time complexity for generating all maximal cliques and computational experiments},
// journal = {Theor. Comput. Sci.},
// volume = {363},
// number = {1},
// year = {2006},
// pages = {28-42}
// ee = {http://dx.doi.org/10.1016/j.tcs.2006.06.015}
// }
/**
* The default clique_visitor supplies an empty visitation function.
*/
struct clique_visitor
{
template <typename VertexSet, typename Graph>
void clique(const VertexSet&, Graph&)
{ }
};
/**
* The max_clique_visitor records the size of the maximum clique (but not the
* clique itself).
*/
struct max_clique_visitor
{
max_clique_visitor(std::size_t& max)
: maximum(max)
{ }
template <typename Clique, typename Graph>
inline void clique(const Clique& p, const Graph& g)
{
maximum = std::max(maximum, p.size());
}
std::size_t& maximum;
};
inline max_clique_visitor find_max_clique(std::size_t& max)
{ return max_clique_visitor(max); }
namespace detail
{
template <typename Graph>
inline bool
is_connected_to_clique(const Graph& g,
typename graph_traits<Graph>::vertex_descriptor u,
typename graph_traits<Graph>::vertex_descriptor v,
typename graph_traits<Graph>::undirected_category)
{
function_requires< AdjacencyMatrixConcept<Graph> >();
return edge(u, v, g).second;
}
template <typename Graph>
inline bool
is_connected_to_clique(const Graph& g,
typename graph_traits<Graph>::vertex_descriptor u,
typename graph_traits<Graph>::vertex_descriptor v,
typename graph_traits<Graph>::directed_category)
{
function_requires< AdjacencyMatrixConcept<Graph> >();
// Note that this could alternate between using an || to determine
// full connectivity. I believe that this should produce strongly
// connected components. Note that using && instead of || will
// change the results to a fully connected subgraph (i.e., symmetric
// edges between all vertices s.t., if a->b, then b->a.
return edge(u, v, g).second && edge(v, u, g).second;
}
template <typename Graph, typename Container>
inline void
filter_unconnected_vertices(const Graph& g,
typename graph_traits<Graph>::vertex_descriptor v,
const Container& in,
Container& out)
{
function_requires< GraphConcept<Graph> >();
typename graph_traits<Graph>::directed_category cat;
typename Container::const_iterator i, end = in.end();
for(i = in.begin(); i != end; ++i) {
if(is_connected_to_clique(g, v, *i, cat)) {
out.push_back(*i);
}
}
}
template <
typename Graph,
typename Clique, // compsub type
typename Container, // candidates/not type
typename Visitor>
void extend_clique(const Graph& g,
Clique& clique,
Container& cands,
Container& nots,
Visitor vis,
std::size_t min)
{
function_requires< GraphConcept<Graph> >();
function_requires< CliqueVisitorConcept<Visitor,Clique,Graph> >();
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
// Is there vertex in nots that is connected to all vertices
// in the candidate set? If so, no clique can ever be found.
// This could be broken out into a separate function.
{
typename Container::iterator ni, nend = nots.end();
typename Container::iterator ci, cend = cands.end();
for(ni = nots.begin(); ni != nend; ++ni) {
for(ci = cands.begin(); ci != cend; ++ci) {
// if we don't find an edge, then we're okay.
if(!edge(*ni, *ci, g).second) break;
}
// if we iterated all the way to the end, then *ni
// is connected to all *ci
if(ci == cend) break;
}
// if we broke early, we found *ni connected to all *ci
if(ni != nend) return;
}
// TODO: the original algorithm 457 describes an alternative
// (albeit really complicated) mechanism for selecting candidates.
// The given optimizaiton seeks to bring about the above
// condition sooner (i.e., there is a vertex in the not set
// that is connected to all candidates). unfortunately, the
// method they give for doing this is fairly unclear.
// basically, for every vertex in not, we should know how many
// vertices it is disconnected from in the candidate set. if
// we fix some vertex in the not set, then we want to keep
// choosing vertices that are not connected to that fixed vertex.
// apparently, by selecting fix point with the minimum number
// of disconnections (i.e., the maximum number of connections
// within the candidate set), then the previous condition wil
// be reached sooner.
// there's some other stuff about using the number of disconnects
// as a counter, but i'm jot really sure i followed it.
// TODO: If we min-sized cliques to visit, then theoretically, we
// should be able to stop recursing if the clique falls below that
// size - maybe?
// otherwise, iterate over candidates and and test
// for maxmimal cliquiness.
typename Container::iterator i, j, end = cands.end();
for(i = cands.begin(); i != cands.end(); ) {
Vertex candidate = *i;
// add the candidate to the clique (keeping the iterator!)
// typename Clique::iterator ci = clique.insert(clique.end(), candidate);
clique.push_back(candidate);
// remove it from the candidate set
i = cands.erase(i);
// build new candidate and not sets by removing all vertices
// that are not connected to the current candidate vertex.
// these actually invert the operation, adding them to the new
// sets if the vertices are connected. its semantically the same.
Container new_cands, new_nots;
filter_unconnected_vertices(g, candidate, cands, new_cands);
filter_unconnected_vertices(g, candidate, nots, new_nots);
if(new_cands.empty() && new_nots.empty()) {
// our current clique is maximal since there's nothing
// that's connected that we haven't already visited. If
// the clique is below our radar, then we won't visit it.
if(clique.size() >= min) {
vis.clique(clique, g);
}
}
else {
// recurse to explore the new candidates
extend_clique(g, clique, new_cands, new_nots, vis, min);
}
// we're done with this vertex, so we need to move it
// to the nots, and remove the candidate from the clique.
nots.push_back(candidate);
clique.pop_back();
}
}
} /* namespace detail */
template <typename Graph, typename Visitor>
inline void
bron_kerbosch_all_cliques(const Graph& g, Visitor vis, std::size_t min)
{
function_requires< IncidenceGraphConcept<Graph> >();
function_requires< VertexListGraphConcept<Graph> >();
function_requires< VertexIndexGraphConcept<Graph> >();
function_requires< AdjacencyMatrixConcept<Graph> >(); // Structural requirement only
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
typedef typename graph_traits<Graph>::vertex_iterator VertexIterator;
typedef std::vector<Vertex> VertexSet;
typedef std::deque<Vertex> Clique;
function_requires< CliqueVisitorConcept<Visitor,Clique,Graph> >();
// NOTE: We're using a deque to implement the clique, because it provides
// constant inserts and removals at the end and also a constant size.
VertexIterator i, end;
tie(i, end) = vertices(g);
VertexSet cands(i, end); // start with all vertices as candidates
VertexSet nots; // start with no vertices visited
Clique clique; // the first clique is an empty vertex set
detail::extend_clique(g, clique, cands, nots, vis, min);
}
// NOTE: By default the minimum number of vertices per clique is set at 2
// because singleton cliques aren't really very interesting.
template <typename Graph, typename Visitor>
inline void
bron_kerbosch_all_cliques(const Graph& g, Visitor vis)
{ bron_kerbosch_all_cliques(g, vis, 2); }
template <typename Graph>
inline std::size_t
bron_kerbosch_clique_number(const Graph& g)
{
std::size_t ret = 0;
bron_kerbosch_all_cliques(g, find_max_clique(ret));
return ret;
}
} /* namespace boost */
#endif

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@@ -16,21 +16,20 @@ namespace boost
struct directed_graph_tag { };
/**
* The directed_graph class template is a simplified version of the BGL
* adjacency list. This class is provided for ease of use, but may not
* perform as well as custom-defined adjacency list classes. Instances of
* this template model the BidirectionalGraph, VertexIndexGraph, and
* EdgeIndexGraph concepts. The graph is also fully mutable, supporting
* both insertions and removals.
*
* @note Special care must be taken when removing vertices or edges since
* those operations can invalidate the numbering of vertices.
*/
* The directed_graph class template is a simplified version of the BGL
* adjacency list. This class is provided for ease of use, but may not
* perform as well as custom-defined adjacency list classes. Instances of
* this template model the BidirectionalGraph, VertexIndexGraph, and
* EdgeIndexGraph concepts. The graph is also fully mutable, supporting
* both insertions and removals of vertices and edges.
*
* @note Special care must be taken when removing vertices or edges since
* those operations can invalidate the numbering of vertices.
*/
template <
typename VertexProperty = no_property,
typename EdgeProperty = no_property,
typename GraphProperty = no_property
>
typename GraphProperty = no_property>
class directed_graph
{
// Wrap the user-specified properties with an index.

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// (C) Copyright 2007-2009 Andrew Sutton
//
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0 (See accompanying file
// LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_GRAPH_CYCLE_HXX
#define BOOST_GRAPH_CYCLE_HXX
#include <vector>
#include <boost/graph/graph_concepts.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/properties.hpp>
#include <boost/concept/detail/concept_def.hpp>
namespace boost {
namespace concepts {
BOOST_concept(CycleVisitor,(Visitor)(Path)(Graph))
{
BOOST_CONCEPT_USAGE(CycleVisitor)
{
vis.cycle(p, g);
}
private:
Visitor vis;
Graph g;
Path p;
};
} /* namespace concepts */
using concepts::CycleVisitorConcept;
} /* namespace boost */
#include <boost/concept/detail/concept_undef.hpp>
namespace boost
{
// The implementation of this algorithm is a reproduction of the Teirnan
// approach for directed graphs: bibtex follows
//
// @article{362819,
// author = {James C. Tiernan},
// title = {An efficient search algorithm to find the elementary circuits of a graph},
// journal = {Commun. ACM},
// volume = {13},
// number = {12},
// year = {1970},
// issn = {0001-0782},
// pages = {722--726},
// doi = {http://doi.acm.org/10.1145/362814.362819},
// publisher = {ACM Press},
// address = {New York, NY, USA},
// }
//
// It should be pointed out that the author does not provide a complete analysis for
// either time or space. This is in part, due to the fact that it's a fairly input
// sensitive problem related to the density and construction of the graph, not just
// its size.
//
// I've also taken some liberties with the interpretation of the algorithm - I've
// basically modernized it to use real data structures (no more arrays and matrices).
// Oh... and there's explicit control structures - not just gotos.
//
// The problem is definitely NP-complete, an an unbounded implementation of this
// will probably run for quite a while on a large graph. The conclusions
// of this paper also reference a Paton algorithm for undirected graphs as being
// much more efficient (apparently based on spanning trees). Although not implemented,
// it can be found here:
//
// @article{363232,
// author = {Keith Paton},
// title = {An algorithm for finding a fundamental set of cycles of a graph},
// journal = {Commun. ACM},
// volume = {12},
// number = {9},
// year = {1969},
// issn = {0001-0782},
// pages = {514--518},
// doi = {http://doi.acm.org/10.1145/363219.363232},
// publisher = {ACM Press},
// address = {New York, NY, USA},
// }
/**
* The default cycle visitor providse an empty visit function for cycle
* visitors.
*/
struct cycle_visitor
{
template <typename Path, typename Graph>
inline void cycle(const Path& p, const Graph& g)
{ }
};
/**
* The min_max_cycle_visitor simultaneously records the minimum and maximum
* cycles in a graph.
*/
struct min_max_cycle_visitor
{
min_max_cycle_visitor(std::size_t& min, std::size_t& max)
: minimum(min), maximum(max)
{ }
template <typename Path, typename Graph>
inline void cycle(const Path& p, const Graph& g)
{
std::size_t len = p.size();
minimum = std::min(minimum, len);
maximum = std::max(maximum, len);
}
std::size_t& minimum;
std::size_t& maximum;
};
inline min_max_cycle_visitor
find_min_max_cycle(std::size_t& min, std::size_t& max)
{ return min_max_cycle_visitor(min, max); }
namespace detail
{
template <typename Graph, typename Path>
inline bool
is_vertex_in_path(const Graph&,
typename graph_traits<Graph>::vertex_descriptor v,
const Path& p)
{
return (std::find(p.begin(), p.end(), v) != p.end());
}
template <typename Graph, typename ClosedMatrix>
inline bool
is_path_closed(const Graph& g,
typename graph_traits<Graph>::vertex_descriptor u,
typename graph_traits<Graph>::vertex_descriptor v,
const ClosedMatrix& closed)
{
// the path from u to v is closed if v can be found in the list
// of closed vertices associated with u.
typedef typename ClosedMatrix::const_reference Row;
Row r = closed[get(vertex_index, g, u)];
if(find(r.begin(), r.end(), v) != r.end()) {
return true;
}
return false;
}
template <typename Graph, typename Path, typename ClosedMatrix>
inline bool
can_extend_path(const Graph& g,
typename graph_traits<Graph>::edge_descriptor e,
const Path& p,
const ClosedMatrix& m)
{
function_requires< IncidenceGraphConcept<Graph> >();
function_requires< VertexIndexGraphConcept<Graph> >();
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
// get the vertices in question
Vertex
u = source(e, g),
v = target(e, g);
// conditions for allowing a traversal along this edge are:
// 1. the index of v must be greater than that at which the
// the path is rooted (p.front()).
// 2. the vertex v cannot already be in the path
// 3. the vertex v cannot be closed to the vertex u
bool indices = get(vertex_index, g, p.front()) < get(vertex_index, g, v);
bool path = !is_vertex_in_path(g, v, p);
bool closed = !is_path_closed(g, u, v, m);
return indices && path && closed;
}
template <typename Graph, typename Path>
inline bool
can_wrap_path(const Graph& g, const Path& p)
{
function_requires< IncidenceGraphConcept<Graph> >();
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
typedef typename graph_traits<Graph>::out_edge_iterator OutIterator;
// iterate over the out-edges of the back, looking for the
// front of the path. also, we can't travel along the same
// edge that we did on the way here, but we don't quite have the
// stringent requirements that we do in can_extend_path().
Vertex
u = p.back(),
v = p.front();
OutIterator i, end;
for(tie(i, end) = out_edges(u, g); i != end; ++i) {
if((target(*i, g) == v)) {
return true;
}
}
return false;
}
template <typename Graph,
typename Path,
typename ClosedMatrix>
inline typename graph_traits<Graph>::vertex_descriptor
extend_path(const Graph& g,
Path& p,
ClosedMatrix& closed)
{
function_requires< IncidenceGraphConcept<Graph> >();
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
typedef typename graph_traits<Graph>::edge_descriptor Edge;
typedef typename graph_traits<Graph>::out_edge_iterator OutIterator;
// get the current vertex
Vertex u = p.back();
Vertex ret = graph_traits<Graph>::null_vertex();
// AdjacencyIterator i, end;
OutIterator i, end;
for(tie(i, end) = out_edges(u, g); i != end; ++i) {
Vertex v = target(*i, g);
// if we can actually extend along this edge,
// then that's what we want to do
if(can_extend_path(g, *i, p, closed)) {
p.push_back(v); // add the vertex to the path
ret = v;
break;
}
}
return ret;
}
template <typename Graph, typename Path, typename ClosedMatrix>
inline bool
exhaust_paths(const Graph& g, Path& p, ClosedMatrix& closed)
{
function_requires< GraphConcept<Graph> >();
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
// if there's more than one vertex in the path, this closes
// of some possible routes and returns true. otherwise, if there's
// only one vertex left, the vertex has been used up
if(p.size() > 1) {
// get the last and second to last vertices, popping the last
// vertex off the path
Vertex last, prev;
last = p.back();
p.pop_back();
prev = p.back();
// reset the closure for the last vertex of the path and
// indicate that the last vertex in p is now closed to
// the next-to-last vertex in p
closed[get(vertex_index, g, last)].clear();
closed[get(vertex_index, g, prev)].push_back(last);
return true;
}
else {
return false;
}
}
template <typename Graph, typename Visitor>
inline void
all_cycles_from_vertex(const Graph& g,
typename graph_traits<Graph>::vertex_descriptor v,
Visitor vis,
std::size_t minlen,
std::size_t maxlen)
{
function_requires< VertexListGraphConcept<Graph> >();
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
typedef std::vector<Vertex> Path;
function_requires< CycleVisitorConcept<Visitor,Path,Graph> >();
typedef std::vector<Vertex> VertexList;
typedef std::vector<VertexList> ClosedMatrix;
Path p;
ClosedMatrix closed(num_vertices(g), VertexList());
Vertex null = graph_traits<Graph>::null_vertex();
// each path investigation starts at the ith vertex
p.push_back(v);
while(1) {
// extend the path until we've reached the end or the
// maxlen-sized cycle
Vertex j = null;
while(((j = detail::extend_path(g, p, closed)) != null)
&& (p.size() < maxlen))
; // empty loop
// if we're done extending the path and there's an edge
// connecting the back to the front, then we should have
// a cycle.
if(detail::can_wrap_path(g, p) && p.size() >= minlen) {
vis.cycle(p, g);
}
if(!detail::exhaust_paths(g, p, closed)) {
break;
}
}
}
// Select the minimum allowable length of a cycle based on the directedness
// of the graph - 2 for directed, 3 for undirected.
template <typename D> struct min_cycles { enum { value = 2 }; };
template <> struct min_cycles<undirected_tag> { enum { value = 3 }; };
} /* namespace detail */
template <typename Graph, typename Visitor>
inline void
tiernan_all_cycles(const Graph& g,
Visitor vis,
std::size_t minlen,
std::size_t maxlen)
{
function_requires< VertexListGraphConcept<Graph> >();
typedef typename graph_traits<Graph>::vertex_iterator VertexIterator;
VertexIterator i, end;
for(tie(i, end) = vertices(g); i != end; ++i) {
detail::all_cycles_from_vertex(g, *i, vis, minlen, maxlen);
}
}
template <typename Graph, typename Visitor>
inline void
tiernan_all_cycles(const Graph& g, Visitor vis, std::size_t maxlen)
{
typedef typename graph_traits<Graph>::directed_category Dir;
tiernan_all_cycles(g, vis, detail::min_cycles<Dir>::value, maxlen);
}
template <typename Graph, typename Visitor>
inline void
tiernan_all_cycles(const Graph& g, Visitor vis)
{
typedef typename graph_traits<Graph>::directed_category Dir;
tiernan_all_cycles(g, vis, detail::min_cycles<Dir>::value,
std::numeric_limits<std::size_t>::max());
}
template <typename Graph>
inline std::pair<std::size_t, std::size_t>
tiernan_girth_and_circumference(const Graph& g)
{
std::size_t
min = std::numeric_limits<std::size_t>::max(),
max = 0;
tiernan_all_cycles(g, find_min_max_cycle(min, max));
// if this is the case, the graph is acyclic...
if(max == 0) max = min;
return std::make_pair(min, max);
}
template <typename Graph>
inline std::size_t
tiernan_girth(const Graph& g)
{ return tiernan_girth_and_circumference(g).first; }
template <typename Graph>
inline std::size_t
tiernan_circumference(const Graph& g)
{ return tiernan_girth_and_circumference(g).second; }
} /* namespace boost */
#endif

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@@ -13,11 +13,23 @@
namespace boost
{
struct undirected_graph_tag { };
struct undirected_graph_tag { };
template <typename VertexProperty = no_property,
typename EdgeProperty = no_property,
typename GraphProperty = no_property>
/**
* The undirected_graph class template is a simplified version of the BGL
* adjacency list. This class is provided for ease of use, but may not
* perform as well as custom-defined adjacency list classes. Instances of
* this template model the VertexIndexGraph, and EdgeIndexGraph concepts. The
* graph is also fully mutable, supporting both insertions and removals of
* vertices and edges.
*
* @note Special care must be taken when removing vertices or edges since
* those operations can invalidate the numbering of vertices.
*/
template <
typename VertexProperty = no_property,
typename EdgeProperty = no_property,
typename GraphProperty = no_property>
class undirected_graph
{
typedef property<vertex_index_t, unsigned, VertexProperty> vertex_property;