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//=======================================================================
// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee,
//
// Distributed under 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)
//=======================================================================
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/breadth_first_search.hpp>
#include <boost/pending/indirect_cmp.hpp>
#include <boost/range/irange.hpp>
#include <boost/property_map/property_map.hpp>
#include <iostream>
using namespace boost;
template < typename TimeMap >
class bfs_time_visitor : public default_bfs_visitor
{
typedef typename property_traits< TimeMap >::value_type T;
public:
bfs_time_visitor(TimeMap tmap, T& t) : m_timemap(tmap), m_time(t) {}
template < typename Vertex, typename Graph >
void discover_vertex(Vertex u, const Graph& g) const
{
put(m_timemap, u, m_time++);
}
TimeMap m_timemap;
T& m_time;
};
struct VertexProps
{
boost::default_color_type color;
std::size_t discover_time;
unsigned int index;
};
int main()
{
using namespace boost;
// Select the graph type we wish to use
typedef adjacency_list< listS, listS, undirectedS, VertexProps > graph_t;
// Set up the vertex IDs and names
enum
{
r,
s,
t,
u,
v,
w,
x,
y,
N
};
const char* name = "rstuvwxy";
// Specify the edges in the graph
typedef std::pair< int, int > E;
E edge_array[] = { E(r, s), E(r, v), E(s, w), E(w, r), E(w, t), E(w, x),
E(x, t), E(t, u), E(x, y), E(u, y) };
// Create the graph object
const int n_edges = sizeof(edge_array) / sizeof(E);
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
// VC++ has trouble with the edge iterator constructor
graph_t g;
std::vector< graph_traits< graph_t >::vertex_descriptor > verts;
for (std::size_t i = 0; i < N; ++i)
verts.push_back(add_vertex(g));
for (std::size_t j = 0; j < n_edges; ++j)
add_edge(verts[edge_array[j].first], verts[edge_array[j].second], g);
#else
typedef graph_traits< graph_t >::vertices_size_type v_size_t;
graph_t g(edge_array, edge_array + n_edges, v_size_t(N));
#endif
// Typedefs
typedef graph_traits< graph_t >::vertices_size_type Size;
Size time = 0;
typedef property_map< graph_t, std::size_t VertexProps::* >::type
dtime_map_t;
dtime_map_t dtime_map = get(&VertexProps::discover_time, g);
bfs_time_visitor< dtime_map_t > vis(dtime_map, time);
breadth_first_search(
g, vertex(s, g), color_map(get(&VertexProps::color, g)).visitor(vis));
// a vector to hold the discover time property for each vertex
std::vector< Size > dtime(num_vertices(g));
typedef iterator_property_map< std::vector< Size >::iterator,
property_map< graph_t, unsigned int VertexProps::* >::type >
dtime_pm_type;
graph_traits< graph_t >::vertex_iterator vi, vi_end;
std::size_t c = 0;
for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi, ++c)
{
dtime[c] = dtime_map[*vi];
put(&VertexProps::index, g, *vi, c);
}
dtime_pm_type dtime_pm(dtime.begin(), get(&VertexProps::index, g));
// Use std::sort to order the vertices by their discover time
std::vector< graph_traits< graph_t >::vertices_size_type > discover_order(
N);
integer_range< int > range(0, N);
std::copy(range.begin(), range.end(), discover_order.begin());
std::sort(discover_order.begin(), discover_order.end(),
make_indirect_cmp(std::less< Size >(),
make_iterator_property_map(
dtime.begin(), typed_identity_property_map< std::size_t >())));
std::cout << "order of discovery: ";
for (int i = 0; i < N; ++i)
std::cout << name[discover_order[i]] << " ";
std::cout << std::endl;
return EXIT_SUCCESS;
}
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