// //======================================================================= // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek // // This file is part of the Generic Graph Component Library // // You should have received a copy of the License Agreement for the // Generic Graph Component Library along with the software; see the // file LICENSE. If not, contact Office of Research, University of Notre // Dame, Notre Dame, IN 46556. // // Permission to modify the code and to distribute modified code is // granted, provided the text of this NOTICE is retained, a notice that // the code was modified is included with the above COPYRIGHT NOTICE and // with the COPYRIGHT NOTICE in the LICENSE file, and that the LICENSE // file is distributed with the modified code. // // LICENSOR MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED. // By way of example, but not limitation, Licensor MAKES NO // REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY // PARTICULAR PURPOSE OR THAT THE USE OF THE LICENSED SOFTWARE COMPONENTS // OR DOCUMENTATION WILL NOT INFRINGE ANY PATENTS, COPYRIGHTS, TRADEMARKS // OR OTHER RIGHTS. //======================================================================= // #include #include #include #include #include #include #include #include #include // for boost::make_list /* Example of using a visitor with the depth first search and breadth first search algorithm Sacramento ---- Reno ---- Salt Lake City | San Francisco | San Jose ---- Fresno | Los Angeles ---- Los Vegas ---- Pheonix | San Diego The visitor has three main functions: discover_vertex(u,g) is invoked when the algorithm first arrives at the vertex u. This will happen in the depth first or breadth first order depending on which algorithm you use. examine_edge(e,g) is invoked when the algorithm first checks an edge to see whether it has already been there. Whether using BFS or DFS, all the edges of vertex u are examined immediately after the call to visit(u). finish_vertex(u,g) is called when after all the vertices reachable from vertex u have already been visited. */ using namespace std; using namespace boost; struct city_arrival : public base_visitor { city_arrival(string* n) : names(n) { } typedef on_discover_vertex event_filter; template inline void operator()(Vertex u, Graph&) { cout << endl << "arriving at " << names[u] << endl << " neighboring cities are: "; } string* names; }; struct neighbor_cities : public base_visitor { neighbor_cities(string* n) : names(n) { } typedef on_examine_edge event_filter; template inline void operator()(Edge e, Graph& g) { cout << names[ target(e, g) ] << ", "; } string* names; }; struct finish_city : public base_visitor { finish_city(string* n) : names(n) { } typedef on_finish_vertex event_filter; template inline void operator()(Vertex u, Graph&) { cout << endl << "finished with " << names[u] << endl; } string* names; }; int main(int, char*[]) { enum { SanJose, SanFran, LA, SanDiego, Fresno, LosVegas, Reno, Sacramento, SaltLake, Pheonix, N }; string names[] = { "San Jose", "San Francisco", "San Jose", "San Francisco", "Los Angeles", "San Diego", "Fresno", "Los Vegas", "Reno", "Sacramento", "Salt Lake City", "Pheonix" }; typedef std::pair E; E edge_array[] = { E(Sacramento, Reno), E(Sacramento, SanFran), E(Reno, SaltLake), E(SanFran, SanJose), E(SanJose, Fresno), E(SanJose, LA), E(LA, LosVegas), E(LA, SanDiego), E(LosVegas, Pheonix) }; /* Create the graph type we want. */ typedef adjacency_list Graph; Graph G(N, edge_array, edge_array + sizeof(edge_array)/sizeof(E)); /* DFS and BFS need to "color" the vertices */ typedef vector colors_t; colors_t colors(N); cout << "*** Depth First ***" << endl; depth_first_search (G, make_dfs_visitor(boost::make_list(city_arrival(names), neighbor_cities(names), finish_city(names))), &colors[0]); cout << endl; /* Get the source vertex */ boost::graph_traits::vertex_descriptor s = vertex(SanJose,G); cout << "*** Breadth First ***" << endl; breadth_first_search (G, s, make_bfs_visitor(boost::make_list(city_arrival(names), neighbor_cities(names), finish_city(names))), &colors[0]); return 0; }