Smallest Subarray with a given sum, in kotlin

SmallestSubarrayWithAGivenSum.kt

/*
Problem Statement #
Given an array of positive numbers and a positive number ‘S’, find the length of the smallest contiguous subarray whose sum is greater than or equal to ‘S’. Return 0, if no such subarray exists.

Example 1:

Input: [2, 1, 5, 2, 3, 2], S=7
Output: 2
Explanation: The smallest subarray with a sum great than or equal to '7' is [5, 2].
Example 2:

Input: [2, 1, 5, 2, 8], S=7
Output: 1
Explanation: The smallest subarray with a sum greater than or equal to '7' is [8].
Example 3:

Input: [3, 4, 1, 1, 6], S=8
Output: 3
Explanation: Smallest subarrays with a sum greater than or equal to '8' are [3, 4, 1] or [1, 1, 6].
 */

fun main() {

    println(findMinSubArray(intArrayOf(2, 1, 5, 2, 3, 2),7))
    println(findMinSubArray(intArrayOf(2, 1, 5, 2, 8),7))
    println(findMinSubArray(intArrayOf(3, 4, 1, 1, 6),8))

}

fun findMinSubArray(array: IntArray, s: Int): Int {
    var start = 0
    var sum = 0
    var output = Int.MAX_VALUE
    array.forEachIndexed { index, i ->
        sum += i
        while (sum >= s) {
            output = output.coerceAtMost(index - start + 1)
            sum -= array[start]
            start++
        }
    }
    return if (output == Int.MAX_VALUE) 0 else output
}