获取相邻顶点的Boost图 [英] Boost Graph Getting Adjacent Vertices

问题描述

我正在使用Boost库进行图形绘制。
该图的定义如下。

  typedef boost :: adjacency_list< boost :: setS，boost :: setS ，boost :: undirectedS，uint32_t，float>邻接表; 
  

使用适当的数据创建图形后，在一个单独的函数中，我想打印每个顶点的adjacent_vertices以及它们在开始时计算的适当的边缘权重。

创建部分工作正常，但是当我想提取相邻顶点时，我不会获取值。

  typedef boost :: graph_traits< AdjacencyList> :: adjacency_iterator AdjacencyIterator; 
 AdjacencyList :: vertex_iterator i，end; 
 for（boost :: tie（i，end）= boost :: vertices（adjacency_list）; i！= end; i ++）{
 AdjacencyIterator ai，a_end; 
 boost :: tie（ai，a_end）= boost :: adjacent_vertices（* i，adjacency_list）; 
 for（; ai！= a_end; ai ++）{
 std :: cout<< * ai<< \t; 
 
 
 $ / code $ / pre 
 $ b $ p我得到的输出是十六进制数的内存地址。 
如何得到顶点索引和边权重？
解决方案
您应该访问属性捆绑包，使用顶点/边描述符或使用属性映射： 
 
 
使用<$ c> 运算符[]  $ c> operator []  
 
 
 
    Live Coliru    
  #include< boost / graph / adjacency_list.hpp> 
 #include< iostream> 
 
 typedef boost :: adjacency_list< boost :: setS，boost :: setS，boost :: undirectedS，uint32_t，float>邻接表; 
 typedef boost :: graph_traits< AdjacencyList> :: adjacency_iterator AdjacencyIterator; 
 
 int main（）{
 AdjacencyList adjacency_list ;; 
 
 boost :: add_edge（
 boost :: add_vertex（10，adjacency_list），
 boost :: add_vertex（20，adjacency_list），
 1.5f，
 adjacency_list 
）; 
 
 boost :: add_edge（
 boost :: add_vertex（30，adjacency_list），
 boost :: add_vertex（40，adjacency_list），
 2.5f，
 adjacency_list 
）; 
 
 AdjacencyList :: vertex_iterator i，end; （boost :: tie（i，end）= boost :: vertices（adjacency_list）; i！= end; i ++）{
 AdjacencyIterator ai，a_end; 
 
 
 
 boost :: tie（ai，a_end）= boost :: adjacent_vertices（* i，adjacency_list）; 
 for（; ai！= a_end; ai ++）{
 std :: cout<< adjacency_list [* ai]<< \t; 
} 
} 
} 
  
输出：
  10 20 30 40 
  
 
 
 
使用属性映射：
 
 
 
  boost :: property_map< AdjacencyList，boost :: vertex_bundle_t> :: type pmap = boost :: get（boost :: vertex_bundle，adjacency_list）; 
  
现在您可以使用 boost :: get（pmap，vertex_descriptor1） code>来访问顶点属性包
 
I am working with a graphing using Boost library.
The graph is defined as follows.
 typedef boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS, uint32_t, float> AdjacencyList;
After creating the graph using appropriate data, in a separate function I want to print the adjacent_vertices of each vertex with their appropriate edge weight as computed in the beginning. 

The creating part works well but when I want to extract adjacent vertices I dont get the values. 
typedef boost::graph_traits<AdjacencyList>::adjacency_iterator AdjacencyIterator;
AdjacencyList::vertex_iterator i, end;
for (boost::tie(i, end) = boost::vertices(adjacency_list); i != end; i++) {
AdjacencyIterator ai, a_end; 
boost::tie(ai, a_end) = boost::adjacent_vertices( *i, adjacency_list);
  for (; ai != a_end; ai++) { 
      std::cout << *ai << "\t";
  }
 }
The Output I get are memory address in Hexademial number. 
How can I get vertex indices and the edge weight?
解决方案
You should access the property bundles, either using the graph's operator[] with the vertex/edge descriptor, or using the property map:

Using the operator[]

Live On Coliru
#include <boost/graph/adjacency_list.hpp>
#include <iostream>

typedef boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS, uint32_t, float> AdjacencyList;
typedef boost::graph_traits<AdjacencyList>::adjacency_iterator AdjacencyIterator;

int main() {
    AdjacencyList adjacency_list;;

    boost::add_edge(
            boost::add_vertex(10, adjacency_list),
            boost::add_vertex(20, adjacency_list),
            1.5f,
            adjacency_list
        );

    boost::add_edge(
            boost::add_vertex(30, adjacency_list),
            boost::add_vertex(40, adjacency_list),
            2.5f,
            adjacency_list
        );

    AdjacencyList::vertex_iterator i, end;

    for (boost::tie(i, end) = boost::vertices(adjacency_list); i != end; i++) {
        AdjacencyIterator ai, a_end; 

        boost::tie(ai, a_end) = boost::adjacent_vertices(*i, adjacency_list);
        for (; ai != a_end; ai++) { 
            std::cout << adjacency_list[*ai] << "\t";
        }
    }
}
Output:
10  20  30  40  


Using the property map:

boost::property_map<AdjacencyList, boost::vertex_bundle_t>::type pmap = boost::get(boost::vertex_bundle, adjacency_list);
Now you can use boost::get(pmap, vertex_descriptor1) to access the vertex property bundle

                        
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