c_cpp 使用带有listS的Boost Graph连接组件

Posted 2021-05-14

typedef boost::adjacency_list<boost::listS,
                              boost::listS,
                              boost::undirectedS,
                              boost::property<boost::vertex_index_t, size_t, VertexProperty>> Graph;
typedef boost::graph_traits<Graph>::vertex_descriptor Vertex;
typedef boost::graph_traits<Graph>::edge_descriptor Edge;
typedef boost::graph_traits<Graph>::vertex_iterator VertexIter;
typedef boost::graph_traits<Graph>::edge_iterator EdgeIter;
typedef boost::shared_ptr<std::vector<unsigned long>> VertexComponentMap;
typedef boost::filtered_graph<Graph,
                              boost::function<bool(Graph::edge_descriptor)>,
                              boost::function<bool(Graph::vertex_descriptor)>> ComponentGraph;

std::vector<ComponentGraph> connectedComponents(Graph &g) {
  boost::property_map<Graph, boost::vertex_index_t>::type index_map = boost::get(boost::vertex_index, g);
  size_t count = 0;
  for (auto v : boost::make_iterator_range(boost::vertices(g)))
    boost::put(index_map, v, count++);

  size_t num = boost::connected_components(g, index_map);

  std::vector<ComponentGraph> componentGraphs;
  for (size_t i = 0; i < num; ++i) {
    componentGraphs.emplace_back(g,
                                 [i, &g, index_map](Graph::edge_descriptor e) {
                                   return boost::get(index_map, boost::source(e, g)) == i ||
                                       boost::get(index_map, boost::target(e, g)) == i;
                                 },
                                 [i, index_map](Graph::vertex_descriptor v) {
                                   return boost::get(index_map, v) == i;
                                 });
  }

  return componentGraphs;
}