open Graph
module G = Pack.Digraph
module Dfs = Graph.Traverse.Dfs(G)

if Array.length Sys.argv != 2 then begin
  Printf.printf "usage: %s max_num_vertices\n" Sys.argv.(0);
  exit 1;
end;

let max_v = int_of_string Sys.argv.(1) in

for v = 2 to max_v do
  for e = 2 to (v*(v-1)) do
    let g = G.Rand.graph ~v ~e () in
    if Dfs.has_cycle g then
      G.dot_output g (Printf.sprintf "graph-%d-%d.dot" v e);
  done;
done;