c++ - 从特定起始顶点 boost prim_minimum_spanning_tree

Question

对于一个简单的图，直接调用 prim_minimum_spanning_tree 得到从顶点 0 开始的结果:

#include <iostream>

#include <boost/graph/graph_traits.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/prim_minimum_spanning_tree.hpp>

typedef boost::property<boost::edge_weight_t, double> EdgeWeightProperty;

typedef boost::adjacency_list<boost::setS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty> Graph;

int main(int,char*[])
{
    // Create a graph object
    Graph g(3);

    EdgeWeightProperty e1 = 5;
    add_edge(0, 1, e1, g);

    EdgeWeightProperty e2 = 3;
    add_edge(1, 2, e2, g);

    std::vector < boost::graph_traits < Graph >::vertex_descriptor > parents(num_vertices(g));

    prim_minimum_spanning_tree(g, &parents[0]);

    for (std::size_t i = 0; i != parents.size(); ++i) {

      if (parents[i] != i) {
        std::cout << "parent[" << i << "] = " << parents[i] << std::endl;
      }
      else {
        std::cout << "parent[" << i << "] = no parent" << std::endl;
      }
    }


    return 0;
}

但我似乎无法解密指定不同起始顶点的签名？看起来这是唯一一个采用 vertex_descriptor 的(我假设它是起始顶点？):

  prim_minimum_spanning_tree
    (const VertexListGraph& g,
     typename graph_traits<VertexListGraph>::vertex_descriptor s, 
     PredecessorMap predecessor, DistanceMap distance, WeightMap weight, 
     IndexMap index_map,
     DijkstraVisitor vis)

关于如何调用它有什么建议吗？

Answer 1

这需要“命名参数”签名:

prim_minimum_spanning_tree(g, &parents[0], boost::root_vertex(1));

您可以在文档页面的“命名参数”下找到可用的命名参数:http://www.boost.org/doc/libs/1_61_0/libs/graph/doc/prim_minimum_spanning_tree.html