LeetCode in Kotlin

1343. Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold

Medium

Given an array of integers arr and two integers k and threshold, return the number of sub-arrays of size k and average greater than or equal to threshold.

Example 1:

Input: arr = [2,2,2,2,5,5,5,8], k = 3, threshold = 4

Output: 3

Explanation: Sub-arrays [2,5,5],[5,5,5] and [5,5,8] have averages 4, 5 and 6 respectively. All other sub-arrays of size 3 have averages less than 4 (the threshold).

Example 2:

Input: arr = [11,13,17,23,29,31,7,5,2,3], k = 3, threshold = 5

Output: 6

Explanation: The first 6 sub-arrays of size 3 have averages greater than 5. Note that averages are not integers.

Constraints:

• 1 <= arr.length <= 105
• 1 <= arr[i] <= 104
• 1 <= k <= arr.length
• 0 <= threshold <= 104

Solution

class Solution {
    fun numOfSubarrays(arr: IntArray, k: Int, threshold: Int): Int {
        var sum = 0
        for (i in 0 until k - 1) {
            sum += arr[i]
        }
        var count = 0
        for (i in k - 1 until arr.size) {
            sum += arr[i]
            if (i - k >= 0) {
                sum -= arr[i - k]
            }
            if (sum / k >= threshold) {
                count++
            }
        }
        return count
    }
}

This site is open source. Improve this page.