Submission #2486360

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Source Code Expand

object Main extends App {
  val Array(h, w) = io.StdIn.readLine().split(' ').map(_.toInt)
  val squares = Array.fill(h+1)(Array.fill(w+1)(0))
  for (i <- 1 to h) {
    val line = io.StdIn.readLine().split(' ').map(_.toInt)
    for (j <- 1 to w) {
      val c = if (((i ^ j) & 1) == 0) line(j-1) else -line(j-1)
      squares(i)(j) += squares(i)(j-1)
      squares(i)(j) += c
    }
  }

  for {
    j <- 1 to w
    i <- 2 to h
  } squares(i)(j) += squares(i-1)(j)
  var max = 0
  for {
    i <- 1 to h
    j <- 1 to w
    ii <- i to h
    jj <- j to w
  } {
    //   h 0 □ □ □ □ □
    //  ii 0 □ ■ ■ ■ □
    //   i 0 □ ■ ■ ■ □
    //     0 □ □ □ □ □
    //   0 0 0 0 0 0 0
    //     0   j   jj w
    if (squares(ii)(jj) - squares(i-1)(jj) - squares(ii)(j-1) + squares(i-1)(j-1) == 0)
      max = Math.max(max, (ii-i+1) * (jj-j+1))
  }
  println(max)
}

Submission Info

Judge Result