Submission #2902897

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Source Code Expand

let () = Scanf.scanf "%d %d\n" @@ fun h w ->
  let acc = Array.make_matrix (h + 1) (w + 1) 0 in
  for i = 1 to h do
    for j = 1 to w do
      Scanf.scanf "%d " @@ fun c ->
        acc.(i).(j) <-
          if i mod 2 = j mod 2 then c else ~- c
    done
  done;
  for i = 1 to h do
    for j = 2 to w do
      acc.(i).(j) <- acc.(i).(j) + acc.(i).(j - 1)
    done
  done;
  for i = 2 to h do
    for j = 1 to w do
      acc.(i).(j) <- acc.(i).(j) + acc.(i - 1).(j)
    done
  done;
  Printf.printf "%d\n" @@
    Array.fold_left (Array.fold_left (Array.fold_left (Array.fold_left max))) 0 @@
      Array.init h @@ fun i ->
        Array.init w @@ fun j ->
          Array.init (i + 1) @@ fun k ->
            Array.init (j + 1) @@ fun l ->
              if acc.(i + 1).(j + 1) - acc.(i + 1).(l) - acc.(k).(j + 1) + acc.(k).(l) = 0 then (i - k + 1) * (j - l + 1) else 0

Submission Info

Judge Result