Boost Graph Library: Prevent DFS from visiting unconnected nodes

问题

I have a bidirectional graph. Some of the vertices are unconnected. I use boost::depth_first_search to traverse the vertices. I also supply the starting source node. I see that the unconnected vertices are also processed after the connected nodes are done. How can I prevent visiting such nodes? In fact, how can I tell DFS to only visit those nodes reachable from the source node and don't visit anything else?

I have the following code:

/// Define vertex properties.
struct NodeProperty
{
    unsigned     id;              /// Id.
    unsigned     kind;            /// Kind.
    unsigned     depth;           /// Depth.
    unsigned     layer_color;     /// Layer color.
    unsigned     signal_color;    /// Signal color.
    unsigned     sch_color;       /// Sch color.
    CBoundingBox bounds;          /// Bounds of polygon.

    NodeProperty()
        : id(0), kind(0), depth(0), layer_color(0), signal_color(0), sch_color(0), bounds(0,0,0,0)
    {
        ;
    }
};
/// Define net topology graph.
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, NodeProperty> Graph;

class receiver_visitor : public boost::default_dfs_visitor
{
    public:
        receiver_visitor(std::vector<Vertex>& r)
            : res(r)
        {
            ;
        }

        void discover_vertex(Vertex v, Graph const& g) const
        {
            std::cout << "Visit: " << v << std::endl;
            if (g[v].sch_color) {
                res.push_back(g[v].sch_color);
            }
        }

        std::vector<Vertex>& res;
 };

 std::vector<std::size_t>
 NetTopology::getReceivers(std::size_t src) const
 {
     std::vector<Vertex> r;
     receiver_visitor vis(r);
     boost::depth_first_search(data_->g, boost::visitor(vis).root_vertex(src));

     return r;
}

回答1:

You want to use depth_first_visit, not depth_first_search.

来源：https://stackoverflow.com/questions/37557241/boost-graph-library-prevent-dfs-from-visiting-unconnected-nodes