| // |
| //======================================================================= |
| // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. |
| // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek |
| // |
| // 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 <vector> |
| #include <string> |
| #include <boost/graph/adjacency_list.hpp> |
| #include <boost/graph/depth_first_search.hpp> |
| #include <boost/graph/breadth_first_search.hpp> |
| #include <boost/property_map/property_map.hpp> |
| #include <boost/graph/graph_utility.hpp> // 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 ---- Las Vegas ---- Phoenix |
| | |
| 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> |
| { |
| city_arrival(string* n) : names(n) { } |
| typedef on_discover_vertex event_filter; |
| template <class Vertex, class Graph> |
| 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> |
| { |
| neighbor_cities(string* n) : names(n) { } |
| typedef on_examine_edge event_filter; |
| template <class Edge, class Graph> |
| inline void operator()(Edge e, Graph& g) { |
| cout << names[ target(e, g) ] << ", "; |
| } |
| string* names; |
| }; |
| |
| struct finish_city : public base_visitor<finish_city> |
| { |
| finish_city(string* n) : names(n) { } |
| typedef on_finish_vertex event_filter; |
| template <class Vertex, class Graph> |
| 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, LasVegas, Reno, |
| Sacramento, SaltLake, Phoenix, N }; |
| |
| string names[] = { "San Jose", "San Francisco", "Los Angeles", "San Diego", |
| "Fresno", "Las Vegas", "Reno", "Sacramento", |
| "Salt Lake City", "Phoenix" }; |
| |
| typedef std::pair<int,int> E; |
| E edge_array[] = { E(Sacramento, Reno), E(Sacramento, SanFran), |
| E(Reno, SaltLake), |
| E(SanFran, SanJose), |
| E(SanJose, Fresno), E(SanJose, LA), |
| E(LA, LasVegas), E(LA, SanDiego), |
| E(LasVegas, Phoenix) }; |
| |
| /* Create the graph type we want. */ |
| typedef adjacency_list<vecS, vecS, undirectedS> Graph; |
| #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 |
| // VC++ has trouble with the edge iterator constructor |
| Graph G(N); |
| for (std::size_t j = 0; j < sizeof(edge_array)/sizeof(E); ++j) |
| add_edge(edge_array[j].first, edge_array[j].second, G); |
| #else |
| Graph G(edge_array, edge_array + sizeof(edge_array)/sizeof(E), N); |
| #endif |
| |
| cout << "*** Depth First ***" << endl; |
| depth_first_search |
| (G, |
| visitor(make_dfs_visitor(boost::make_list(city_arrival(names), |
| neighbor_cities(names), |
| finish_city(names))))); |
| cout << endl; |
| |
| /* Get the source vertex */ |
| boost::graph_traits<Graph>::vertex_descriptor |
| s = vertex(SanJose,G); |
| |
| cout << "*** Breadth First ***" << endl; |
| breadth_first_search |
| (G, s, visitor(make_bfs_visitor(boost::make_list(city_arrival(names), |
| neighbor_cities(names), |
| finish_city(names))))); |
| |
| return 0; |
| } |