Re: [Boost-users] Identify cycles in a undirected graph

Subject: Re: [Boost-users] Identify cycles in a undirected graph
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2012-02-08 13:17:18

On Wed, 8 Feb 2012, NsPx wrote:

> Hi all,
> 
> I use undirected_dfs to detect all cycles in a undirected graph.
> I detect a cycle with DFSVisitor.back_edge(e,g) but how can I get the list of vertices defining this cycle ?

Keep a predecessor map using predecessor_recorder, then walk the chain of 
predecessors from the target of the back_edge to its source.  The vertices 
you iterate through are your cycle.  Reading 
http://www.me.utexas.edu/~bard/IP/Handouts/cycles.pdf gives the algorithm 
and why it works in more detail.

-- Jeremiah Willcock