On Mon, 24 Jun 2013, lizy10b wrote:
Hi there I have a problem with the DFS method (Boost 1.53). 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....) 1) Change the graph type from "bidirectionalS" to "undirected". 2)Implement all the 8 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