C++ boost::graph 从有向图中获取父顶点

我有一个有向图（通过 boost::graph 库中的 adjacency_graph 实现），我试图找到某个顶点的父顶点。

过去（通过 pygraph）我只是简单地反转了有向图，然后进行了邻居搜索，但似乎使用 boost::reverse_graph 反转图会将我的有向图变成双向图，因此我无法使用adjacent_vertices方法不再了。

有没有更好的方法来获取父顶点？

Thanks.

这是我当前的示例代码：

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/reverse_graph.hpp>
#include <iostream>

typedef boost::adjacency_list< boost::setS, boost::vecS, boost::directedS > Graph;
typedef boost::reverse_graph<Graph> Rgraph;
typedef Graph::vertex_descriptor Vertex;

int main()
{
    Graph graph;
    Vertex v0 = boost::add_vertex(graph);
    Vertex v1 = boost::add_vertex(graph);
    Vertex v2 = boost::add_vertex(graph);
    Vertex v3 = boost::add_vertex(graph);
    Vertex v4 = boost::add_vertex(graph);
    Vertex v5 = boost::add_vertex(graph);
    Vertex v6 = boost::add_vertex(graph);

    boost::add_edge(v0,v1,graph);
    boost::add_edge(v1,v2,graph);
    boost::add_edge(v2,v3,graph);
    boost::add_edge(v2,v4,graph);
    boost::add_edge(v3,v5,graph);
    boost::add_edge(v4,v5,graph);
    boost::add_edge(v5,v6,graph);

    Graph::adjacency_iterator ibegin, iend;
    for (boost::tie(ibegin, iend) = boost::adjacent_vertices(v2, graph); ibegin != iend; ++ibegin)
    {
        std::cout << *ibegin << std::endl;
    }

    std::cout << std::endl << "############# RGRAPH #############" << std::endl << std::endl;

    Rgraph rgraph(graph);
    Rgraph::adjacency_iterator rbegin, rend;
    for (boost::tie(rbegin, rend) = boost::adjacent_vertices(v2, rgraph); rbegin != rend; ++rbegin)
    {
        std::cout << *rbegin << std::endl;
    }
    std::cout << std::endl;

    return 0;
}

reverse_graph http://www.boost.org/libs/graph/doc/reverse_graph.html要求调整后的图是以下模型BidirectionalGraph http://www.boost.org/libs/graph/doc/BidirectionalGraph.html。如果您将图表更改为typedef boost::adjacency_list< boost::setS, boost::vecS, boost::bidirectionalS > Graph;你的程序编译并给出结果：

3
4

############# RGRAPH #############

1

我相信这是你应该期待的。

另一种方法不需要reverse_graph（但仍然需要bidirectionalS）是使用：

Graph::out_edge_iterator out_begin, out_end;
for (boost::tie(out_begin, out_end) = out_edges(v2,graph); out_begin != out_end; ++out_begin)
{   
    std::cout << target(*out_begin,graph) << std::endl;
}
std::cout << std::endl;

Graph::in_edge_iterator in_begin, in_end;
for (boost::tie(in_begin, in_end) = in_edges(v2,graph); in_begin != in_end; ++in_begin)
{   
    std::cout << source(*in_begin,graph) << std::endl;
}
std::cout << std::endl;