Hi all,

I would like to build a visitor (for dikstra) with the initialise_vertex acting as 'colour map' modifier.

I want to exclude some vertices from the search based on a condition.

So I want to set some vertices 'black' in the init part of the algorithm.

class dijkstra_2step : public boost::default_dijkstra_visitor

{

public:

    dijkstra_2step(std::vector<Weight> dists, double threshold): distances(dists), threshold(threshold) {}

// THIS PART IS NOT CORRECT!!!! //

    void initialize_vertex(boost::graph_traits <unGraph>::vertex_descriptor u, const unGraph& g){

        if( distances[u] > threshold ) color[u] = black; // ??????

    }

//////////

    std::vector<Weight> distances;

    double threshold;

};

Any help for the above visitor? How to I access the colour?

I couldn't find something online.

Thanks