graph/example/kevin-bacon.cpp

118 lines
3.4 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 <iostream>
#include <fstream>
#include <string>
#include <boost/tokenizer.hpp>
#include <boost/tuple/tuple.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/visitors.hpp>
#include <boost/graph/breadth_first_search.hpp>
#include <map>
using namespace boost;
template <typename DistanceMap>
class bacon_number_recorder : public default_bfs_visitor
{
public:
bacon_number_recorder(DistanceMap dist) : d(dist) { }
template <typename Edge, typename Graph>
void tree_edge(Edge e, const Graph& g) const
{
typename graph_traits<Graph>::vertex_descriptor
u = source(e, g), v = target(e, g);
d[v] = d[u] + 1;
}
private:
DistanceMap d;
};
// Convenience function
template < typename DistanceMap >
bacon_number_recorder<DistanceMap>
record_bacon_number(DistanceMap d)
{
return bacon_number_recorder < DistanceMap > (d);
}
int
main(int argc, const char** argv)
{
std::ifstream datafile(argc >= 2 ? argv[1] : "./kevin-bacon.dat");
if (!datafile) {
std::cerr << "No ./kevin-bacon.dat file" << std::endl;
return EXIT_FAILURE;
}
typedef adjacency_list < vecS, vecS, undirectedS, property < vertex_name_t,
std::string >, property < edge_name_t, std::string > > Graph;
Graph g;
typedef property_map < Graph, vertex_name_t >::type actor_name_map_t;
actor_name_map_t actor_name = get(vertex_name, g);
typedef property_map < Graph, edge_name_t >::type movie_name_map_t;
movie_name_map_t connecting_movie = get(edge_name, g);
typedef graph_traits < Graph >::vertex_descriptor Vertex;
typedef std::map < std::string, Vertex > NameVertexMap;
NameVertexMap actors;
for (std::string line; std::getline(datafile, line);) {
char_delimiters_separator < char >sep(false, "", ";");
tokenizer <> line_toks(line, sep);
tokenizer <>::iterator i = line_toks.begin();
std::string actors_name = *i++;
NameVertexMap::iterator pos;
bool inserted;
Vertex u, v;
boost::tie(pos, inserted) = actors.insert(std::make_pair(actors_name, Vertex()));
if (inserted) {
u = add_vertex(g);
actor_name[u] = actors_name;
pos->second = u;
} else
u = pos->second;
std::string movie_name = *i++;
boost::tie(pos, inserted) = actors.insert(std::make_pair(*i, Vertex()));
if (inserted) {
v = add_vertex(g);
actor_name[v] = *i;
pos->second = v;
} else
v = pos->second;
graph_traits < Graph >::edge_descriptor e;
boost::tie(e, inserted) = add_edge(u, v, g);
if (inserted)
connecting_movie[e] = movie_name;
}
std::vector < int >bacon_number(num_vertices(g));
Vertex src = actors["Kevin Bacon"];
bacon_number[src] = 0;
breadth_first_search(g, src,
visitor(record_bacon_number(&bacon_number[0])));
graph_traits < Graph >::vertex_iterator i, end;
for (boost::tie(i, end) = vertices(g); i != end; ++i) {
std::cout << actor_name[*i] << " has a Bacon number of "
<< bacon_number[*i] << std::endl;
}
return 0;
}