Re: [Boost-users] [BGL] BFS visitor question

From: Jeremy Graham Siek (jsiek_at_[hidden])
Date: 2005-08-02 14:27:27

Hi Rui,

You need to throw and exception. (the FAQ explains this a bit more)

Cheers,
Jeremy

On Aug 2, 2005, at 2:17 PM, Rui Carvalho wrote:
> Hello,
>
> I'm using the BFS visitor that appears in the BGL book (p 66), which 
> can
> also be found here:
> http://boost.org/libs/graph/doc/kevin_bacon.html
>
> I would like to compute a quantity that depends on the bacon number of 
> a
> vertex, but only to distance d_max as my graphs are quite big (and I 
> need to
> compute the quantity for each vertex, so I want a speedy computation).
> Ideally, I'd like to write something like the code below (my code 
> appears
> after the comment), but this doesn't seem to work. Am I missing 
> something
> basic?
>
>   template <typename DistanceMap>
>   class bacon_number_recorder : public default_bfs_visitor
>   {
>   public:
>     bacon_number_recorder(DistanceMap dist) : d(dist) { }
>
>     template <typename Edge, typename Graph>
>     void tree_edge(Edge e, const Graph& g) const
>     {
>       typename graph_traits<Graph>::vertex_descriptor
> 	u = source(e, g), v = target(e, g);
> 	d[v] = d[u] + 1;
> 	//end BFS if v is at a distance greater than d_max
> 	if (d[v]>dmax)
> 		return;
>     }
>   private:
>       DistanceMap d;
>   };
>
>
>
> Thanks,
> Rui
>
>
>
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_______________________________________________
Jeremy Siek <Jeremy.G.Siek_at_[hidden]>
http://www.cs.rice.edu/~jgs3847
Post-Doc, Rice University
_______________________________________________