Re: [Boost-users] [BGL] graph copy after Kruskal's algorithm?

10 Mar 2006


      Douglas Gregor wrote:
...
On Mar 6, 2006, at 12:23 AM, Alejandro Aragón wrote:
...
Doug,
I tried to follow your directions but I coundn't find any concrete
example of using the get(vertex_all,orig,v) function.  I did something
else, but I think it is not working.  Could you give me further
directions to code it your way?
This is what I came up with:
// minimum_spanning_graph
Graph* graph::minimum_spanning_graph(std::vector<Edge>& spanning_tree)
{
     // create an empty graph
     // the original graph has pointer gPtr
     Graph* copy = new Graph();
// iterate over all vertices in the original graph
     Vertex v_new;
     for (tie(vi, vi_end) = vertices(*gPtr); vi != vi_end; ++vi){
  v_new = add_vertex(*copy);
I think you can change this line to:
v_new = add_vertex(get(vertex_all, *gPtr, *vi), *copy);
...
coordmap[v_new] = coordmap[*vi];
     }
// iterate over all the edges in the list produced by algorithm
     bool inserted;
     Edge e_new;
     for (std::vector < Edge >::iterator ei = spanning_tree.begin();
   ei != spanning_tree.end(); ++ei) {
  tie(e_new,inserted) = add_edge(source(*ei,*gPtr),target 
(*ei,*gPtr),*copy);
And then change this line to:
tie(e_new, inserted) = add_edge(source(*ei, *gPtr), target(*ei,  
*gPtr), get(edge_all, *gPtr, *ei), *copy);
...
weightmap[e_new] = weightmap[*ei];
  anglemap[e_new] = anglemap[*ei];
     }
std::cout<<"Number of edges in original graph =
"<
      

        
          
          
        
        

    
    
    
		
			
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