I managed to create a visitor now, however, instead of speeding things
up dijkstra_shortest_paths now runs several orders of magnitudes slower!
I created the visitor according to the bfs_name_printer example in the
BGL User Guide and Reference Book page 11.
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class dijkstra_finish : public Exception {
};
template<unsigned maxdist>
class MyVisitor : public default_dijkstra_visitor {
public:
MyVisitor(const vector<unsigned> &d_) : d(d_) {}
template
void finish_vertex(Vertex u, Graph g) {
if (d[u]> maxdist) throw dijkstra_finish();
}
private:
const vector<unsigned> &d;
};
struct Distance {
unsigned d;
};
int main() {
vector<unsigned> dists(num_edges(g));
MyVisitor(dists);
try {
dijkstra_shortest_paths(g,source_vertex,weight_map(get(&Distance::d,g)).distance_map(make_iterator_property_map(dists.begin(),get(vertex_index,g))).visitor(vis2));
} catch(const dijkstra_finish&) {}
}
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The code seems to do what I want, all dists are either 0,1,2,3 or
numeric_limits<unsigned>::max(). But for a graph with 15000 edges it
takes a few ms to run dijkstra without a visitor but with it it takes 14
seconds. What am I doing wrong?
