Hi Jeremiah Willcock ,
 
It seems undirected_dfs() works. I have not check the result according to the graph, but at least there is no forward edge or cross edge output.
Attached is the revised cpp file using undirected_dfs() .
My question is why edge_color_map(get(edge_color, g))  is required when calling the undirected_dfs() .
Thanks
 
Zhiyu Li
 
 
2013-06-25
lizy10b
发件人： Jeremiah Willcock
发送时间： 2013-06-24  23:47:20
收件人： boost-users
抄送： lizy10b
主题： Re: [Boost-users] Confused with Depth-First-Search method, forwardor cross edge found on a undirected graph ?
On Mon, 24 Jun 2013, lizy10b wrote:
> Hi?there
> I?have?a?problem?with?the?DFS?method?Boost?.53).?
> I?found?when?invoking?the?DFS?method?on?a?undirected?graph,?the?forward_or_cross_edge"?was?called?more?than?one?ti
> mes.?
> But?as?the?document?says?In?an?undirected?graph?this?method?is?never?called".
> http://www.boost.org/doc/libs/1_53_0/libs/graph/doc/DFSVisitor.html
> ?
> I?performed?the?test?based?on?the?file_dependencies.cpp?example
> ?examples/file_dependencies.cpp;?http://www.boost.org/doc/libs/1_53_0/libs/graph/doc/file_dependency_example.html)
> 1)
> Change?the?graph?type?from?bidirectionalS"?to?undirected".
> 2)Implement?all?the??DFS?vistor?event?methods"?Initialize?Vertex,?Start?Vertex,?Discover?Vertex,?Examine?Edge,?T
> ree?Edge,?Back?Edge,?Forward?or?Cross?Edge,?Finish?Vertex)
> in?the cycle_detector?struct?to?print?the?vertex?names,?edge?sources?and?targets.
> 3)comment?out?some?code?at?the?begining?of?the?example
> cpp?files?as?the?topological_sort?method?raise?exception?upon?the?undirected?graph.
Does undirected_dfs() do the same thing?  I don't think the directed 
version should call forward_or_cross_edge when given an undirected graph, 
though.  Would it be possible for you to print out the vertex->color 
mapping when forward_or_cross_edge is called?  Also, it would be nice if 
you'd send your complete test program.  Thanks.
-- Jeremiah Willcock