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vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/graph/distributed/connected_components.hpp

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// Copyright (C) 2004-2006 The Trustees of Indiana University.
// 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)
// Authors: Nick Edmonds
// Douglas Gregor
// Andrew Lumsdaine
#ifndef BOOST_GRAPH_PARALLEL_CC_HPP
#define BOOST_GRAPH_PARALLEL_CC_HPP
#ifndef BOOST_GRAPH_USE_MPI
#error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included"
#endif
#include <boost/detail/is_sorted.hpp>
#include <boost/assert.hpp>
#include <boost/property_map/property_map.hpp>
#include <boost/property_map/parallel/caching_property_map.hpp>
#include <boost/graph/parallel/algorithm.hpp>
#include <boost/pending/indirect_cmp.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/overloading.hpp>
#include <boost/graph/distributed/concepts.hpp>
#include <boost/graph/parallel/properties.hpp>
#include <boost/graph/distributed/local_subgraph.hpp>
#include <boost/graph/connected_components.hpp>
#include <boost/graph/named_function_params.hpp>
#include <boost/graph/parallel/process_group.hpp>
#include <boost/optional.hpp>
#include <functional>
#include <algorithm>
#include <vector>
#include <list>
#include <boost/graph/parallel/container_traits.hpp>
#include <boost/graph/iteration_macros.hpp>
#define PBGL_IN_PLACE_MERGE /* In place merge instead of sorting */
//#define PBGL_SORT_ASSERT /* Assert sorted for in place merge */
/* Explicit sychronization in pointer doubling step? */
#define PBGL_EXPLICIT_SYNCH
//#define PBGL_CONSTRUCT_METAGRAPH
#ifdef PBGL_CONSTRUCT_METAGRAPH
# define MAX_VERTICES_IN_METAGRAPH 10000
#endif
namespace boost { namespace graph { namespace distributed {
namespace cc_detail {
enum connected_components_message {
edges_msg, req_parents_msg, parents_msg, root_adj_msg
};
template <typename Vertex>
struct metaVertex {
metaVertex() {}
metaVertex(const Vertex& v) : name(v) {}
template<typename Archiver>
void serialize(Archiver& ar, const unsigned int /*version*/)
{
ar & name;
}
Vertex name;
};
#ifdef PBGL_CONSTRUCT_METAGRAPH
// Build meta-graph on result of local connected components
template <typename Graph, typename ParentMap, typename RootIterator,
typename AdjacencyMap>
void
build_local_metagraph(const Graph& g, ParentMap p, RootIterator r,
RootIterator r_end, AdjacencyMap& adj)
{
// TODO: Static assert that AdjacencyMap::value_type is std::vector<vertex_descriptor>
typedef typename boost::graph::parallel::process_group_type<Graph>::type
process_group_type;
typedef typename process_group_type::process_id_type process_id_type;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
BOOST_STATIC_ASSERT((is_same<typename AdjacencyMap::mapped_type,
std::vector<vertex_descriptor> >::value));
using boost::graph::parallel::process_group;
process_group_type pg = process_group(g);
process_id_type id = process_id(pg);
if (id != 0) {
// Send component roots and their associated edges to P0
for ( ; r != r_end; ++r ) {
std::vector<vertex_descriptor> adjs(1, *r); // Root
adjs.reserve(adjs.size() + adj[*r].size());
for (typename std::vector<vertex_descriptor>::iterator iter = adj[*r].begin();
iter != adj[*r].end(); ++iter)
adjs.push_back(get(p, *iter)); // Adjacencies
send(pg, 0, root_adj_msg, adjs);
}
}
synchronize(pg);
if (id == 0) {
typedef metaVertex<vertex_descriptor> VertexProperties;
typedef boost::adjacency_list<vecS, vecS, undirectedS,
VertexProperties> metaGraph;
typedef typename graph_traits<metaGraph>::vertex_descriptor
meta_vertex_descriptor;
std::map<vertex_descriptor, meta_vertex_descriptor> vertex_map;
std::vector<std::pair<vertex_descriptor, vertex_descriptor> > edges;
// Receive remote roots and edges
while (optional<std::pair<process_id_type, int> > m = probe(pg)) {
BOOST_ASSERT(m->second == root_adj_msg);
std::vector<vertex_descriptor> adjs;
receive(pg, m->first, m->second, adjs);
vertex_map[adjs[0]] = graph_traits<metaGraph>::null_vertex();
for (typename std::vector<vertex_descriptor>::iterator iter
= ++adjs.begin(); iter != adjs.end(); ++iter)
edges.push_back(std::make_pair(adjs[0], *iter));
}
// Add local roots and edges
for ( ; r != r_end; ++r ) {
vertex_map[*r] = graph_traits<metaGraph>::null_vertex();
edges.reserve(edges.size() + adj[*r].size());
for (typename std::vector<vertex_descriptor>::iterator iter = adj[*r].begin();
iter != adj[*r].end(); ++iter)
edges.push_back(std::make_pair(*r, get(p, *iter)));
}
// Build local meta-graph
metaGraph mg;
// Add vertices with property to map back to distributed graph vertex
for (typename std::map<vertex_descriptor, meta_vertex_descriptor>::iterator
iter = vertex_map.begin(); iter != vertex_map.end(); ++iter)
vertex_map[iter->first]
= add_vertex(metaVertex<vertex_descriptor>(iter->first), mg);
// Build meta-vertex map
typename property_map<metaGraph, vertex_descriptor VertexProperties::*>::type
metaVertexMap = get(&VertexProperties::name, mg);
typename std::vector<std::pair<vertex_descriptor, vertex_descriptor> >
::iterator edge_iter = edges.begin();
for ( ; edge_iter != edges.end(); ++edge_iter)
add_edge(vertex_map[edge_iter->first], vertex_map[edge_iter->second], mg);
edges.clear();
// Call connected_components on it
typedef typename property_map<metaGraph, vertex_index_t>::type
meta_index_map_type;
meta_index_map_type meta_index = get(vertex_index, mg);
std::vector<std::size_t> mg_component_vec(num_vertices(mg));
typedef iterator_property_map<std::vector<std::size_t>::iterator,
meta_index_map_type>
meta_components_map_type;
meta_components_map_type mg_component(mg_component_vec.begin(),
meta_index);
std::size_t num_comp = connected_components(mg, mg_component);
// Update Parent pointers
std::vector<meta_vertex_descriptor> roots(num_comp, graph_traits<metaGraph>::null_vertex());
BGL_FORALL_VERTICES_T(v, mg, metaGraph) {
size_t component = get(mg_component, v);
if (roots[component] == graph_traits<metaGraph>::null_vertex() ||
get(meta_index, v) < get(meta_index, roots[component]))
roots[component] = v;
}
// Set all the local parent pointers
BGL_FORALL_VERTICES_T(v, mg, metaGraph) {
// Problem in value being put (3rd parameter)
put(p, get(metaVertexMap, v), get(metaVertexMap, roots[get(mg_component, v)]));
}
}
synchronize(p);
}
#endif
/* Function object used to remove internal vertices and vertices >
the current vertex from the adjacent vertex lists at each
root */
template <typename Vertex, typename ParentMap>
class cull_adjacency_list
{
public:
cull_adjacency_list(const Vertex v, const ParentMap p) : v(v), p(p) {}
bool operator() (const Vertex x) { return (get(p, x) == v || x == v); }
private:
const Vertex v;
const ParentMap p;
};
/* Comparison operator used to choose targets for hooking s.t. vertices
that are hooked to are evenly distributed across processors */
template <typename OwnerMap, typename LocalMap>
class hashed_vertex_compare
{
public:
hashed_vertex_compare (const OwnerMap& o, const LocalMap& l)
: owner(o), local(l) { }
template <typename Vertex>
bool operator() (const Vertex x, const Vertex y)
{
if (get(local, x) < get(local, y))
return true;
else if (get(local, x) == get(local, y))
return (get(owner, x) < get(owner, y));
return false;
}
private:
OwnerMap owner;
LocalMap local;
};
#ifdef PBGL_EXPLICIT_SYNCH
template <typename Graph, typename ParentMap, typename VertexList>
void
request_parent_map_entries(const Graph& g, ParentMap p,
std::vector<VertexList>& parent_requests)
{
typedef typename boost::graph::parallel::process_group_type<Graph>
::type process_group_type;
typedef typename process_group_type::process_id_type process_id_type;
typedef typename graph_traits<Graph>::vertex_descriptor
vertex_descriptor;
process_group_type pg = process_group(g);
/*
This should probably be send_oob_with_reply, especially when Dave
finishes prefetch-batching
*/
// Send root requests
for (process_id_type i = 0; i < num_processes(pg); ++i) {
if (!parent_requests[i].empty()) {
std::vector<vertex_descriptor> reqs(parent_requests[i].begin(),
parent_requests[i].end());
send(pg, i, req_parents_msg, reqs);
}
}
synchronize(pg);
// Receive root requests and reply to them
while (optional<std::pair<process_id_type, int> > m = probe(pg)) {
std::vector<vertex_descriptor> requests;
receive(pg, m->first, m->second, requests);
for (std::size_t i = 0; i < requests.size(); ++i)
requests[i] = get(p, requests[i]);
send(pg, m->first, parents_msg, requests);
}
synchronize(pg);
// Receive requested parents
std::vector<vertex_descriptor> responses;
for (process_id_type i = 0; i < num_processes(pg); ++i) {
if (!parent_requests[i].empty()) {
receive(pg, i, parents_msg, responses);
std::size_t parent_idx = 0;
for (typename VertexList::iterator v = parent_requests[i].begin();
v != parent_requests[i].end(); ++v, ++parent_idx)
put(p, *v, responses[parent_idx]);
}
}
}
#endif
template<typename DistributedGraph, typename ParentMap>
void
parallel_connected_components(DistributedGraph& g, ParentMap p)
{
using boost::connected_components;
typedef typename graph_traits<DistributedGraph>::adjacency_iterator
adjacency_iterator;
typedef typename graph_traits<DistributedGraph>::vertex_descriptor
vertex_descriptor;
typedef typename boost::graph::parallel::process_group_type<DistributedGraph>
::type process_group_type;
typedef typename process_group_type::process_id_type process_id_type;
using boost::graph::parallel::process_group;
process_group_type pg = process_group(g);
process_id_type id = process_id(pg);
// TODO (NGE): Should old_roots, roots, and completed_roots be std::list
adjacency_iterator av1, av2;
std::vector<vertex_descriptor> old_roots;
typename std::vector<vertex_descriptor>::iterator liter;
typename std::vector<vertex_descriptor>::iterator aliter;
typename std::map<vertex_descriptor,
std::vector<vertex_descriptor> > adj;
typedef typename property_map<DistributedGraph, vertex_owner_t>::const_type
OwnerMap;
OwnerMap owner = get(vertex_owner, g);
typedef typename property_map<DistributedGraph, vertex_local_t>::const_type
LocalMap;
LocalMap local = get(vertex_local, g);
// We need to hold on to all of the parent pointers
p.set_max_ghost_cells(0);
//
// STAGE 1 : Compute local components
//
local_subgraph<const DistributedGraph> ls(g);
typedef typename property_map<local_subgraph<const DistributedGraph>,
vertex_index_t>::type local_index_map_type;
local_index_map_type local_index = get(vertex_index, ls);
// Compute local connected components
std::vector<std::size_t> ls_components_vec(num_vertices(ls));
typedef iterator_property_map<std::vector<std::size_t>::iterator,
local_index_map_type>
ls_components_map_type;
ls_components_map_type ls_component(ls_components_vec.begin(),
local_index);
std::size_t num_comp = connected_components(ls, ls_component);
std::vector<vertex_descriptor>
roots(num_comp, graph_traits<DistributedGraph>::null_vertex());
BGL_FORALL_VERTICES_T(v, g, DistributedGraph) {
size_t component = get(ls_component, v);
if (roots[component] == graph_traits<DistributedGraph>::null_vertex() ||
get(local_index, v) < get(local_index, roots[component]))
roots[component] = v;
}
// Set all the local parent pointers
BGL_FORALL_VERTICES_T(v, g, DistributedGraph) {
put(p, v, roots[get(ls_component, v)]);
}
if (num_processes(pg) == 1) return;
// Build adjacency list for all roots
BGL_FORALL_VERTICES_T(v, g, DistributedGraph) {
std::vector<vertex_descriptor>& my_adj = adj[get(p, v)];
for (boost::tie(av1, av2) = adjacent_vertices(v, g);
av1 != av2; ++av1) {
if (get(owner, *av1) != id) my_adj.push_back(*av1);
}
}
// For all vertices adjacent to a local vertex get p(v)
for ( liter = roots.begin(); liter != roots.end(); ++liter ) {
std::vector<vertex_descriptor>& my_adj = adj[*liter];
for ( aliter = my_adj.begin(); aliter != my_adj.end(); ++aliter )
request(p, *aliter);
}
synchronize(p);
// Update adjacency list at root to make sure all adjacent
// vertices are roots of remote components
for ( liter = roots.begin(); liter != roots.end(); ++liter )
{
std::vector<vertex_descriptor>& my_adj = adj[*liter];
for ( aliter = my_adj.begin(); aliter != my_adj.end(); ++aliter )
*aliter = get(p, *aliter);
my_adj.erase
(std::remove_if(my_adj.begin(), my_adj.end(),
cull_adjacency_list<vertex_descriptor,
ParentMap>(*liter, p) ),
my_adj.end());
// This sort needs to be here to make sure the initial
// adjacency list is sorted
std::sort(my_adj.begin(), my_adj.end(), std::less<vertex_descriptor>());
my_adj.erase(std::unique(my_adj.begin(), my_adj.end()), my_adj.end());
}
// Get p(v) for the new adjacent roots
p.clear();
for ( liter = roots.begin(); liter != roots.end(); ++liter ) {
std::vector<vertex_descriptor>& my_adj = adj[*liter];
for ( aliter = my_adj.begin(); aliter != my_adj.end(); ++aliter )
request(p, *aliter);
}
#ifdef PBGL_EXPLICIT_SYNCH
synchronize(p);
#endif
// Lastly, remove roots with no adjacent vertices, this is
// unnecessary but will speed up sparse graphs
for ( liter = roots.begin(); liter != roots.end(); /*in loop*/)
{
if ( adj[*liter].empty() )
liter = roots.erase(liter);
else
++liter;
}
#ifdef PBGL_CONSTRUCT_METAGRAPH
/* TODO: If the number of roots is sufficiently small, we can
use a 'problem folding' approach like we do in MST
to gather all the roots and their adjacencies on one proc
and solve for the connected components of the meta-graph */
using boost::parallel::all_reduce;
std::size_t num_roots = all_reduce(pg, roots.size(), std::plus<std::size_t>());
if (num_roots < MAX_VERTICES_IN_METAGRAPH) {
build_local_metagraph(g, p, roots.begin(), roots.end(), adj);
// For each vertex in g, p(v) = p(p(v)), assign parent of leaf
// vertices from first step to final parent
BGL_FORALL_VERTICES_T(v, g, DistributedGraph) {
put(p, v, get(p, get(p, v)));
}
synchronize(p);
return;
}
#endif
//
// Parallel Phase
//
std::vector<vertex_descriptor> completed_roots;
hashed_vertex_compare<OwnerMap, LocalMap> v_compare(owner, local);
bool any_hooked;
vertex_descriptor new_root;
std::size_t steps = 0;
do {
++steps;
// Pull in new parents for hooking phase
synchronize(p);
//
// Hooking
//
bool hooked = false;
completed_roots.clear();
for ( liter = roots.begin(); liter != roots.end(); )
{
new_root = graph_traits<DistributedGraph>::null_vertex();
std::vector<vertex_descriptor>& my_adj = adj[*liter];
for ( aliter = my_adj.begin(); aliter != my_adj.end(); ++aliter )
// try to hook to better adjacent vertex
if ( v_compare( get(p, *aliter), *liter ) )
new_root = get(p, *aliter);
if ( new_root != graph_traits<DistributedGraph>::null_vertex() )
{
hooked = true;
put(p, *liter, new_root);
old_roots.push_back(*liter);
completed_roots.push_back(*liter);
liter = roots.erase(liter);
}
else
++liter;
}
//
// Pointer jumping, perform until new roots determined
//
// TODO: Implement cycle reduction rules to reduce this from
// O(n) to O(log n) [n = cycle length]
bool all_done;
std::size_t parent_root_count;
std::size_t double_steps = 0;
do {
++double_steps;
#ifndef PBGL_EXPLICIT_SYNCH
// Get p(p(v)) for all old roots, and p(v) for all current roots
for ( liter = old_roots.begin(); liter != old_roots.end(); ++liter )
request(p, get(p, *liter));
synchronize(p);
#else
// Build root requests
typedef std::set<vertex_descriptor> VertexSet;
std::vector<VertexSet> parent_requests(num_processes(pg));
for ( liter = old_roots.begin(); liter != old_roots.end(); ++liter )
{
vertex_descriptor p1 = *liter;
if (get(owner, p1) != id) parent_requests[get(owner, p1)].insert(p1);
vertex_descriptor p2 = get(p, p1);
if (get(owner, p2) != id) parent_requests[get(owner, p2)].insert(p2);
}
request_parent_map_entries(g, p, parent_requests);
#endif
// Perform a pointer jumping step on all old roots
for ( liter = old_roots.begin(); liter != old_roots.end(); ++liter )
put(p, *liter, get(p, get(p, *liter)));
// make sure the parent of all old roots is itself a root
parent_root_count = 0;
for ( liter = old_roots.begin(); liter != old_roots.end(); ++liter )
if ( get(p, *liter) == get(p, get(p, *liter)) )
parent_root_count++;
bool done = parent_root_count == old_roots.size();
all_reduce(pg, &done, &done+1, &all_done,
std::logical_and<bool>());
} while ( !all_done );
#ifdef PARALLEL_BGL_DEBUG
if (id == 0) std::cerr << double_steps << " doubling steps.\n";
#endif
//
// Add adjacent vertices of just completed roots to adjacent
// vertex list at new parent
//
typename std::vector<vertex_descriptor> outgoing_edges;
for ( liter = completed_roots.begin(); liter != completed_roots.end();
++liter )
{
vertex_descriptor new_parent = get(p, *liter);
if ( get(owner, new_parent) == id )
{
std::vector<vertex_descriptor>& my_adj = adj[new_parent];
my_adj.reserve(my_adj.size() + adj[*liter].size());
my_adj.insert( my_adj.end(),
adj[*liter].begin(), adj[*liter].end() );
#ifdef PBGL_IN_PLACE_MERGE
#ifdef PBGL_SORT_ASSERT
BOOST_ASSERT(::boost::detail::is_sorted(my_adj.begin(),
my_adj.end() - adj[*liter].size(),
std::less<vertex_descriptor>()));
BOOST_ASSERT(::boost::detail::is_sorted(my_adj.end() - adj[*liter].size(),
my_adj.end(),
std::less<vertex_descriptor>()));
#endif
std::inplace_merge(my_adj.begin(),
my_adj.end() - adj[*liter].size(),
my_adj.end(),
std::less<vertex_descriptor>());
#endif
}
else if ( adj[*liter].begin() != adj[*liter].end() )
{
outgoing_edges.clear();
outgoing_edges.reserve(adj[*liter].size() + 1);
// First element is the destination of the adjacency list
outgoing_edges.push_back(new_parent);
outgoing_edges.insert(outgoing_edges.end(),
adj[*liter].begin(), adj[*liter].end() );
send(pg, get(owner, new_parent), edges_msg, outgoing_edges);
adj[*liter].clear();
}
}
synchronize(pg);
// Receive edges sent by remote nodes and add them to the
// indicated vertex's adjacency list
while (optional<std::pair<process_id_type, int> > m
= probe(pg))
{
std::vector<vertex_descriptor> incoming_edges;
receive(pg, m->first, edges_msg, incoming_edges);
typename std::vector<vertex_descriptor>::iterator aviter
= incoming_edges.begin();
++aviter;
std::vector<vertex_descriptor>& my_adj = adj[incoming_edges[0]];
my_adj.reserve(my_adj.size() + incoming_edges.size() - 1);
my_adj.insert( my_adj.end(), aviter, incoming_edges.end() );
#ifdef PBGL_IN_PLACE_MERGE
std::size_t num_incoming_edges = incoming_edges.size();
#ifdef PBGL_SORT_ASSERT
BOOST_ASSERT(::boost::detail::is_sorted(my_adj.begin(),
my_adj.end() - (num_incoming_edges-1),
std::less<vertex_descriptor>()));
BOOST_ASSERT(::boost::detail::is_sorted(my_adj.end() - (num_incoming_edges-1),
my_adj.end(),
std::less<vertex_descriptor>()));
#endif
std::inplace_merge(my_adj.begin(),
my_adj.end() - (num_incoming_edges - 1),
my_adj.end(),
std::less<vertex_descriptor>());
#endif
}
// Remove any adjacent vertices that are in the same component
// as a root from that root's list
for ( liter = roots.begin(); liter != roots.end(); ++liter )
{
// We can probably get away without sorting and removing
// duplicates Though sorting *may* cause root
// determination to occur faster by choosing the root with
// the most potential to hook to at each step
std::vector<vertex_descriptor>& my_adj = adj[*liter];
my_adj.erase
(std::remove_if(my_adj.begin(), my_adj.end(),
cull_adjacency_list<vertex_descriptor,
ParentMap>(*liter, p) ),
my_adj.end());
#ifndef PBGL_IN_PLACE_MERGE
std::sort(my_adj.begin(), my_adj.end(),
std::less<vertex_descriptor>() );
#endif
my_adj.erase(std::unique(my_adj.begin(), my_adj.end()), my_adj.end());
}
// Reduce result of empty root list test
all_reduce(pg, &hooked, &hooked+1, &any_hooked,
std::logical_or<bool>());
} while ( any_hooked );
#ifdef PARALLEL_BGL_DEBUG
if (id == 0) std::cerr << steps << " iterations.\n";
#endif
//
// Finalize
//
// For each vertex in g, p(v) = p(p(v)), assign parent of leaf
// vertices from first step to final parent
BGL_FORALL_VERTICES_T(v, g, DistributedGraph) {
put(p, v, get(p, get(p, v)));
}
synchronize(p);
}
} // end namespace cc_detail
template<typename Graph, typename ParentMap, typename ComponentMap>
typename property_traits<ComponentMap>::value_type
number_components_from_parents(const Graph& g, ParentMap p, ComponentMap c)
{
typedef typename graph_traits<Graph>::vertex_descriptor
vertex_descriptor;
typedef typename boost::graph::parallel::process_group_type<Graph>::type
process_group_type;
typedef typename property_traits<ComponentMap>::value_type
ComponentMapType;
process_group_type pg = process_group(g);
/* Build list of roots */
std::vector<vertex_descriptor> my_roots, all_roots;
BGL_FORALL_VERTICES_T(v, g, Graph) {
if( std::find( my_roots.begin(), my_roots.end(), get(p, v) )
== my_roots.end() )
my_roots.push_back( get(p, v) );
}
all_gather(pg, my_roots.begin(), my_roots.end(), all_roots);
/* Number components */
std::map<vertex_descriptor, ComponentMapType> comp_numbers;
ComponentMapType c_num = 0;
// Compute component numbers
for (std::size_t i = 0; i < all_roots.size(); i++ )
if ( comp_numbers.count(all_roots[i]) == 0 )
comp_numbers[all_roots[i]] = c_num++;
// Broadcast component numbers
BGL_FORALL_VERTICES_T(v, g, Graph) {
put( c, v, comp_numbers[get(p, v)] );
}
// Broadcast number of components
if (process_id(pg) == 0) {
typedef typename process_group_type::process_size_type
process_size_type;
for (process_size_type dest = 1, n = num_processes(pg);
dest != n; ++dest)
send(pg, dest, 0, c_num);
}
synchronize(pg);
if (process_id(pg) != 0) receive(pg, 0, 0, c_num);
synchronize(c);
return c_num;
}
template<typename Graph, typename ParentMap>
int
number_components_from_parents(const Graph& g, ParentMap p,
dummy_property_map)
{
using boost::parallel::all_reduce;
// Count local roots.
int num_roots = 0;
BGL_FORALL_VERTICES_T(v, g, Graph)
if (get(p, v) == v) ++num_roots;
return all_reduce(g.process_group(), num_roots, std::plus<int>());
}
template<typename Graph, typename ComponentMap, typename ParentMap>
typename property_traits<ComponentMap>::value_type
connected_components
(const Graph& g, ComponentMap c, ParentMap p
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, distributed_graph_tag))
{
cc_detail::parallel_connected_components(g, p);
return number_components_from_parents(g, p, c);
}
/* Construct ParentMap by default */
template<typename Graph, typename ComponentMap>
typename property_traits<ComponentMap>::value_type
connected_components
( const Graph& g, ComponentMap c
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, distributed_graph_tag) )
{
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
std::vector<vertex_descriptor> x(num_vertices(g));
return connected_components
(g, c,
make_iterator_property_map(x.begin(), get(vertex_index, g)));
}
} // end namespace distributed
using distributed::connected_components;
} // end namespace graph
using graph::distributed::connected_components;
} // end namespace boost
#endif // BOOST_GRAPH_PARALLEL_CC_HPP
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