Giulio,
Here's an idea. You say you want to list all the vertices that make up any one of the (potentially very numerours) cycles that originate on a vertex X. If _any_ cycle will do, how about the shortest? You can use Dijkstra. From http://www.boost.org/libs/graph/doc/dijkstra_shortest_paths.html: "Also you can record the shortest paths tree in a predecessor map: for each vertex u in V, p[u] will be the predecessor of u in the shortest paths tree (unless p[u] = u, in which case u is either the source or a vertex unreachable from the source)."
I don't think Dijkstra will work on a path that looks like V->X->Y->U->V (ie, a cycle). But, to get around this, you do know that U->V is an edge, so you can compute the shortest path between V and U, and know that there's an edge between U and V.
HTH, Andrea
-- Andrea Olgiati - Elixent - Castlemead, Lwr Castle St., Bristol BS1 3AG, UK andrea.olgiati@elixent.com ++44 (0)117 9175612 <snip> Nice trick! (just remember to snip long quotes) That could probably be generalised with a bit of effort, may be useful to someone (like the
Andrea Olgiati wrote: poor OP :D).