Submission #2995799

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Source Code Expand

let rec for_sum a b f v = if a > b then v else for_sum (a+1) b f (v + f a)
let () = Scanf.scanf "%d %d" @@ fun n m ->
  let g = Array.init (n+1) (fun _ -> []) in
  for _ = 1 to m do
    Scanf.scanf " %d %d" @@ fun u v ->
    g.(u) <- v :: g.(u); g.(v) <- u :: g.(v);
  done;
  let mem = Array.make (n+1) false in
  let rec dfs u p =
    mem.(u) <- true;
    List.fold_left (fun m v ->
      if v = p then m
      else if mem.(v) then 0
      else dfs v u * m) 1 g.(u)
  in
  for_sum 1 n (fun i -> if mem.(i) then 0 else dfs i 0) 0
  |> Printf.printf "%d\n"

Submission Info

Judge Result