问题
帖子底部的代码打印出来:
Vertices in g = [ 0 1 2 3 4 ]
Vertices in g' = [ 0 1 ]
我期望的输出是:
Vertices in g = [ 0 1 2 3 4 ]
Vertices in g' = [ 3 4 ]
这是 boost::subgraph 中的错误还是我对库的理解错误?
有问题的代码
#include <sstream>
#include <iostream>
#include <boost/graph/subgraph.hpp>
#include <boost/graph/adjacency_list.hpp>
using namespace std;
using namespace boost;
// Underlying graph representation and implementation
typedef adjacency_list_traits<vecS, vecS, directedS> Traits;
// Graph representation
typedef subgraph< adjacency_list<vecS, vecS, directedS,
property<vertex_color_t, int>, property<edge_index_t, int> > > Graph;
// Iterating over vertices and edges
typedef graph_traits<Graph>::vertex_iterator vertex_iter;
typedef graph_traits<Graph>::edge_iterator edge_iter;
int main(void)
{
Graph g;
add_edge(0,1, g);
add_edge(1,2, g);
add_edge(3,4, g);
Graph sub = g.create_subgraph();
add_vertex(3, sub);
add_vertex(4, sub);
pair<vertex_iter, vertex_iter> vip;
cout << "Vertices in g = [ ";
vip = vertices(g);
for(vertex_iter vi = vip.first; vi != vip.second; ++vi) {
cout << *vi << " ";
}
cout << "]" << endl;
cout << "Vertices in g' = [ ";
vip = vertices(sub);
for(vertex_iter vi = vip.first; vi != vip.second; ++vi) {
cout << *vi << " ";
}
cout << "]" << endl;
return 0;
}
最佳答案
我懒得看文档了。 boost::subgraph 区分“本地”和“全局”描述符。
add_vertex 函数在向子图添加顶点时使用全局描述符。 vertices() 函数返回局部描述符。
我需要做的是在子图上使用方法 local_to_global() 将局部描述符“解析”为我期望的全局描述符。
输出:
Vertices in g = [ 0 1 2 3 4 ]
Vertices (local) in g' = [ 0 1 ]
Vertices (global) in g' = [ 3 4 ]
来自代码:
#include <sstream>
#include <iostream>
#include <boost/graph/subgraph.hpp>
#include <boost/graph/adjacency_list.hpp>
using namespace std;
using namespace boost;
// Underlying graph representation and implementation
typedef adjacency_list_traits<vecS, vecS, directedS> Traits;
// Graph representation
typedef subgraph< adjacency_list<vecS, vecS, directedS,
property<vertex_color_t, int>, property<edge_index_t, int> > > Graph;
// Iterating over vertices and edges
typedef graph_traits<Graph>::vertex_iterator vertex_iter;
typedef graph_traits<Graph>::edge_iterator edge_iter;
int main(void)
{
Graph g;
add_edge(0,1, g);
add_edge(1,2, g);
add_edge(3,4, g);
Graph sub = g.create_subgraph();
add_vertex(3, sub);
add_vertex(4, sub);
pair<vertex_iter, vertex_iter> vip;
cout << "Vertices in g = [ ";
vip = vertices(g);
for(vertex_iter vi = vip.first; vi != vip.second; ++vi) {
cout << *vi << " ";
}
cout << "]" << endl;
cout << "Vertices (local) in g' = [ ";
vip = vertices(sub);
for(vertex_iter vi = vip.first; vi != vip.second; ++vi) {
cout << *vi << " ";
}
cout << "]" << endl;
cout << "Vertices (global) in g' = [ ";
vip = vertices(sub);
for(vertex_iter vi = vip.first; vi != vip.second; ++vi) {
cout << sub.local_to_global(*vi) << " ";
}
cout << "]" << endl;
return 0;
}
关于c++ - boost::subgraph 中的顶点问题,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/23650821/