Hi, I must be missing something basic as my use of random_vertex returns always the same vertex each time I run the code (which is listed below). Help would be much appreciated. I'm using MSVC 7.1 and boost 1.32 on windows XP. TIA, Rui #include <iostream> #include <boost/graph/random.hpp> #include <boost/random/mersenne_twister.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graph_traits.hpp> using namespace boost; using namespace std; int main(int,char*[]) { typedef adjacency_list < vecS, vecS, directedS > Graph; //Builds graph with vertices, but no edges Graph g(100); typedef graph_traits<Graph>::vertex_descriptor Vertex; mt19937 gen; Vertex i; i = random_vertex(g, gen); cout << "Random vertex:" << i << endl; }