graph/example/default-constructor2.cpp

50 lines
1.6 KiB
C++

//=======================================================================
// 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/config.hpp>
#include <fstream>
#include <boost/graph/adjacency_list.hpp>
using namespace boost;
template < typename Graph > void
read_graph_file(std::istream & in, Graph & g)
{
typedef typename graph_traits < Graph >::vertex_descriptor Vertex;
typedef typename graph_traits < Graph >::vertices_size_type size_type;
size_type n_vertices;
in >> n_vertices; // read in number of vertices
std::vector < Vertex > vertex_set(n_vertices);
for (size_type i = 0; i < n_vertices; ++i)
vertex_set[i] = add_vertex(g);
size_type u, v;
while (in >> u)
if (in >> v)
add_edge(vertex_set[u], vertex_set[v], g);
else
break;
}
int
main(int argc, const char** argv)
{
typedef adjacency_list < listS, // Store out-edges of each vertex in a std::list
vecS, // Store vertex set in a std::vector
directedS // The graph is directed
> graph_type;
graph_type g; // use default constructor to create empty graph
std::ifstream file_in(argc >= 2 ? argv[1] : "makefile-dependencies.dat");
read_graph_file(file_in, g);
assert(num_vertices(g) == 15);
assert(num_edges(g) == 19);
return 0;
}