Re: [Boost-users] [graph] breadth_first_search with a structure

Hello Stephan, Am 12.09.2006 um 12:42 Uhr haben Sie geschrieben:
typedef adjacency_list < vecS, vecS, undirectedS, tVertex> tGraph;
after that you get a property map from the graph: typedef property_map<graph_t, long tVertex::*>::type tDistanceMap;
I think "graph_t" should be "tGraph", shouldn't ist? When compiling your example, the VC++ compiler puts a lot of Errors: :\daten\Programme\boost/pending/property.hpp(40) : error C2039: 'kind' : is not a member of '`global namespace'' H:\daten\Programme\boost/graph/properties.hpp(198) : see reference to class template instantiation 'boost::property_kind<long dreiDmatrix::tVertex::*>' being compiled H:\daten\Programme\Matrizen\dreiDmatrix.cpp(255) : see reference to class template instantiation 'boost::property_map<class boost::adjacency_list<struct boost::vecS,struct boost::vecS,struct boost::undirectedS,struct dreiDmatrix::tVertex,str uct boost::no_property,struct boost::no_property,struct boost::listS>,long dreiDmatrix::tVertex::*>' being compiled ... and so on. What`s wrong? Thank you.

Hi Daniel, 2006/9/12, boost@daniel-gohlke.de <boost@daniel-gohlke.de>:
Hello Stephan,
Am 12.09.2006 um 12:42 Uhr haben Sie geschrieben:
typedef adjacency_list < vecS, vecS, undirectedS, tVertex> tGraph;
after that you get a property map from the graph: typedef property_map<graph_t, long tVertex::*>::type tDistanceMap;
I think "graph_t" should be "tGraph", shouldn't ist?
Yep, typo. Sorry. Actually there was another one in the visitor. So, here again a full example of how I would do it (including the exception thrown if a max-distance was discovered) Please try this one (it's the altered bfs-example): #include <boost/graph/adjacency_list.hpp> #include <boost/graph/breadth_first_search.hpp> #include <boost/pending/integer_range.hpp> #include <iostream> using namespace boost; //tag for throwing inside bfs_distance_visitor struct max_distance_reached{}; template < typename DistanceMap > class bfs_distance_visitor:public default_bfs_visitor { typedef typename property_traits < DistanceMap >::value_type T; public: bfs_distance_visitor(DistanceMap dmap, T max_distance):m_distance_map(dmap),m_max_distance(max_distance){ } template < typename Edge, typename Graph > void tree_edge(Edge e, const Graph & g) const { typename graph_traits < Graph >::vertex_descriptor s = source(e, g), t = target(e, g); m_distance_map[t] = m_distance_map[s] + 1; if (m_distance_map[t] >= m_max_distance) throw max_distance_reached(); } DistanceMap m_distance_map; T m_max_distance; }; //own vertex, bundles properties style struct Vertex{ long distance; double probability; }; int main() { // Select the graph type we wish to use typedef adjacency_list < vecS, vecS, undirectedS, Vertex> graph_t; // Set up the vertex IDs and names enum { r, s, t, u, v, w, x, y, N }; // 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); typedef graph_traits<graph_t>::vertices_size_type v_size_t; graph_t g(edge_array, edge_array + n_edges, v_size_t(N)); // Typedefs typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor ; typedef graph_traits < graph_t >::vertices_size_type vertices_size_type; // get the distance property map from the graph typedef property_map<graph_t, long Vertex::*>::type tDistanceMap; tDistanceMap distance_map = get(&Vertex::distance, g); //create a bfs visitor which calculates all distances smaller than 3 bfs_distance_visitor<tDistanceMap> vis(distance_map, 3); try{ breadth_first_search(g, vertex(s, g), visitor(vis)); } catch(max_distance_reached& ){} return EXIT_SUCCESS; } If this won't compile, please specify also which version of boost and VC++ you are using. HTH, Stephan
participants (2)
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boost@daniel-gohlke.de
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Stephan Diederich