Thanks for sharing what you learned Luca. I'm sure others will run into the same problem. Also, to further explain the difference between a bidirectionalS, undirectedS, and directedS adjacency_list: The bidirectionalS type is for representing directed graphs and provides efficient access to both out-edges and in-edges. The undirectedS is for undirected graphs but also provides both in-edges and out-edges. The directedS is for directed graphs, and only provides access to out_edges. Cheers, Jeremy On Thu, 24 Jan 2002, lucatoldo wrote: luca.t> I would like to inform all users of the boost system that as expected luca.t> was my mistake. Infact, the library and the bfs.cpp work exactely as luca.t> to be expected given the semantic of the methods used. luca.t> luca.t> The very patient and creative Jeremy have explained me in the luca.t> meantime that I was using the wrong class type for my need. luca.t> luca.t> If I use the undirectedS instead of the bidirectionalS in the typedef luca.t> of the adjacency_list, then I get exactely the behaviour and the luca.t> result that I needed/expected. luca.t> luca.t> The mistake I was doing was to assume that "bidirectionalS" luca.t> and "undirectedS" be the same thing. Indeed they are not. luca.t> luca.t> Again, a mistake of a beginner with very limited knowledge in graphs luca.t> and very limited knowledge in C++. luca.t> luca.t> Thanks to your patience I got my wheel running now, and it is a luca.t> powerful stimulus for adding depth to my knowledge. For this reason, luca.t> I am now looking forward your excellent Graph book that I ordered luca.t> yesterday. luca.t> luca.t> I will post on this mailing list as soon as the paper (describing the luca.t> study which also makes use of the boost library) is accepted for luca.t> publication. luca.t> luca.t> Regards luca.t> luca.t> Luca ---------------------------------------------------------------------- Jeremy Siek http://php.indiana.edu/~jsiek/ Ph.D. Student, Indiana Univ. B'ton email: jsiek@osl.iu.edu C++ Booster (http://www.boost.org) office phone: (812) 855-3608 ----------------------------------------------------------------------