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- //
- //=======================================================================
- // 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;
- }
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