Hello Doug, I am trying to create a custom visitor class, for bfs, which accumulates all predecessors (based on Doug Gregor's suggestion for finding all paths between 2 vertices) I compiled and ran this example from the examples dir. However, the output is not consistent with kevin_bacon.expected in the example dir. Output I get is listed below (top lines) $ a.out William Shatner has a Bacon number of 0 has a Bacon number of 1 Denise Richards has a Bacon number of 0 has a Bacon number of 0 Patrick Stewart has a Bacon number of 0 has a Bacon number of 0 Steve Martin has a Bacon number of 0 Gerard Depardieu has a Bacon number of 0 has a Bacon number of 0 Clint Howard has a Bacon number of 0 Sean Astin has a Bacon number of 0 ..... (basically, all values are zero) except the first. http://www.boost.org/libs/graph/example/kevin-bacon.cpp I am using boost version 1.33.0/x86_64/include/boost-1_33 gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-52) If possible, can someone please check whether the output you get is the correct one ? regards, -harsh