Submission #2827728

---

Source Code Expand

let () =
  Scanf.scanf "%d" @@ fun n ->
  let s = Array.init n (fun i ->
    if i = 0 then (0, i)
    else begin
      Printf.printf "? 1 %d\n%!" (i+1);
      Scanf.scanf " %d" (fun x -> x, i)
    end)
    |> Array.fold_left max (-1, -1) |> snd
  in
  let diam = Array.init n (fun i ->
    if i = s then (0, i)
    else begin
      Printf.printf "? %d %d\n%!" (s+1) (i+1);
      Scanf.scanf " %d" (fun x -> x, i)
    end)
    |> Array.fold_left max (-1, -1) |> fst
  in Printf.printf "! %d\n%!" diam

Submission Info

Judge Result