boost::graph库的最短路径算法使用示例

大概是2006年的代码，仅做参考。

#include <boost/config.hpp>
#include <iostream>
#include <fstream>

#include <boost/graph/graph_traits.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>

using namespace boost;

int main(int, char *[])
{
	typedef adjacency_list < listS, vecS, directedS,
		no_property, property < edge_weight_t, int > > graph_t;
	typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor;
	typedef graph_traits < graph_t >::edge_descriptor edge_descriptor;
	typedef std::pair<int, int> Edge;
	
	const int num_nodes = 5;
	enum nodes { A, B, C, D, E };
	char name[] = "ABCDE";
	Edge edge_array[] = { Edge(A, C), Edge(B, B), Edge(B, D), Edge(B, E),
		Edge(C, B), Edge(C, D), Edge(D, E), Edge(E, A), Edge(E, B)
	};
	int weights[] = { 1, 2, 1, 2, 7, 3, 1, 1, 1 };
	int num_arcs = sizeof(edge_array) / sizeof(Edge);
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
	graph_t g(num_nodes);
	property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g);
	for (std::size_t j = 0; j < num_arcs; ++j) {
		edge_descriptor e; bool inserted;
		tie(e, inserted) = add_edge(edge_array[j].first, edge_array[j].second, g);
		weightmap[e] = weights[j];
	}
#else
	graph_t g(edge_array, edge_array + num_arcs, weights, num_nodes);
	property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g);
#endif
	std::vector<vertex_descriptor> p(num_vertices(g));
	std::vector<int> d(num_vertices(g));
	vertex_descriptor s = vertex(A, g);
	
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
	// VC++ has trouble with the named parameters mechanism
	property_map<graph_t, vertex_index_t>::type indexmap = get(vertex_index, g);
	dijkstra_shortest_paths(g, s, &p[0], &d[0], weightmap, indexmap, 
		std::less<int>(), closed_plus<int>(), 
		(std::numeric_limits<int>::max)(), 0,
		default_dijkstra_visitor());
#else
	dijkstra_shortest_paths(g, s, predecessor_map(&p[0]).distance_map(&d[0]));
#endif
	
	std::cout << "distances and parents:" << std::endl;
	graph_traits < graph_t >::vertex_iterator vi, vend;
	for (tie(vi, vend) = vertices(g); vi != vend; ++vi) {
		std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << ", ";
		std::cout << "parent(" << name[*vi] << ") = " << name[p[*vi]] << std::
			endl;
	}
	std::cout << std::endl;
	
	std::ofstream dot_file("figs/dijkstra-eg.dot");
	
	dot_file << "digraph D {\n"
		<< "  rankdir=LR\n"
		<< "  size=\"4,3\"\n"
		<< "  ratio=\"fill\"\n"
		<< "  edge[style=\"bold\"]\n" << "  node[shape=\"circle\"]\n";
	
	graph_traits < graph_t >::edge_iterator ei, ei_end;
	for (tie(ei, ei_end) = edges(g); ei != ei_end; ++ei) {
		graph_traits < graph_t >::edge_descriptor e = *ei;
		graph_traits < graph_t >::vertex_descriptor
			u = source(e, g), v = target(e, g);
		dot_file << name[u] << " -> " << name[v]
			<< "[label=\"" << get(weightmap, e) << "\"";
		if (p[v] == u)
			dot_file << ", color=\"black\"";
		else
			dot_file << ", color=\"grey\"";
		dot_file << "]";
	}
	dot_file << "}";
	return EXIT_SUCCESS;
}