Use this if you are using igraph from R
Create adjacency lists from a graph, either for adjacent edges or for neighboring vertices
as_adj_list(graph, mode = c("all", "out", "in", "total"))
as_adj_edge_list(graph, mode = c("all", "out", "in", "total"))
graph | 
 The input graph.  | 
mode | 
 Character scalar, it gives what kind of adjacent edges/vertices
to include in the lists. ‘  | 
as_adj_list returns a list of numeric vectors, which include the ids
of neighbor vertices (according to the mode argument) of all
vertices.
as_adj_edge_list returns a list of numeric vectors, which include the
ids of adjacent edgs (according to the mode argument) of all
vertices.
A list of numeric vectors.
Gabor Csardi csardi.gabor@gmail.com
g <- make_ring(10) as_adj_list(g) as_adj_edge_list(g)