On Feb 13, 2006, at 4:56 PM, David Brumley wrote:
for(i = 0; i < 50; i++){ array[i] = i + 0x8000000; } [snip] for(i = 0; i < 50; i++){ add_edge(array[i % 50], array[ (i+1) % 50], g); } }
[snip]
What am I doing wrong here? I would like to index each node in the graph by its address, which is in the range 0x8000000-0xffffffff. (I would rather not keep a separate index in the range 0-num(verticies)).
add_edge(u, v, g) works on vertex "descriptors", which abstractly represent the vertex. Descriptors are somewhat like indices, but with adjacency_list<> class decides how to do the indexing. When the VertexListS template argument to adjacency_list is "vecS" (as in your example), the vertex descriptors are values in [0, num_vertices(g)). In that specific case, add_edge(u, v, g) has some interesting behavior when u and v are values >= the number of vertices in the graph: it silently expands the graph to accommodate u and v as vertices. So those add_edge calls are trying to allocate another space for 134M vertices, hence the bad_alloc. Since the graph type essentially gets to decide what the descriptors will be, you'll probably need to have an external mapping from addresses to vertex descriptors. Doug