On Sat, May 2, 2015 at 2:47 AM, Rossano Schifanella wrote:

Hi all,

which is the easiest way to extract from a graph G and a generic node source a subgraph with all the vertices/edges at distance at most n from source?

Thanks a lot for your help. Best, Rossano

I'm assuming that you've already figured this out given that it's been quite a while, but it's an easy question to answer so I figured I'd leave the answer here for posterity. In the sequential case, customize a BFS visitor to throw an exception on the first path encountered longer than n. In the parallel case you could either add an all_reduce per epoch to the algorithm explicitly or customize the queue to embed the 'terminate_early?' predicate into the distributed queue. This is (IMHO) the canonical way to handle depth-limited searches in BGL and a method that I find myself using repeatedly. It's so trivial to implement (at least in the sequential case) that I've never felt that it warranted a separate algorithm. Regards, Nick