How to search for an element in an array while passing state for the next iteration

Search.scala

  val numbers = readLine().split(" ").map(_.toInt) // an array of numbers
  val leftSums = numbers.scan(0)(_ + _).init // calculate cumulative sums from left

  // search from right to find the same sum from left
  var sum = 0
  val result = numbers.zipWithIndex.reverse.find { case (number, index) =>
    if (sum == leftSums(index)) true
    else {
      sum = sum + number
      false
    }
  }

@metanet my answer for @korayal applies to you. And also this: https://twitter.com/fehmicans/status/593039964268552192