1343-number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold.java

class Solution {
    public int numOfSubarrays(int[] arr, int k, int threshold) {
        int res = 0, currSum = 0;

        for (int i = 0; i < k - 1; i++) {
            currSum += arr[i];
        }

        for (int l = 0; l < arr.length - k + 1; l++) {
            currSum += arr[l + k - 1];
            if ((currSum / k) >= threshold) {
                res++;
            }
            currSum -= arr[l];
        }
        return res;
    }
}