maxDifference.kt

fun maxDifference(arr: Array<Int>): Int {

    var min: Pair<Int, Int> = Pair(0, 0)
    var max: Pair<Int, Int> = Pair(0, 0)
    var result = -1

    for(i in 0 until arr.size) {
        when {
            i == 0 -> {
                min = Pair(i, arr[i])
                max = Pair(i, arr[i])
            }
            min.second > arr[i] -> min = Pair(i, arr[i])
            arr[i] > min.second -> max = Pair(i, arr[i])
        }

        if(max.first > min.first && max.second > min.second)
            result = kotlin.math.max(result, max.second - min.second)
    }

    return result
}