Boost Graph Library：阻止DFS访问未连接的节点

Question

我有双向图。一些顶点是未连接的。我使用 boost :: depth_first_search 来遍历顶点。我还提供了起始源节点。我看到在连接的节点完成后也会处理未连接的顶点。如何防止访问此类节点？实际上，如何告诉DFS只访问从源节点可以访问的节点而不访问其他任何节点？

我有以下代码：

/// 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;
}

Answer 1

您想使用depth_first_visit，而不是depth_first_search。