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

class Solution:
    def numOfSubarrays(self, arr: List[int], k: int, threshold: int) -> int:
        res = 0
        curSum = sum(arr[:k-1])

        for L in range(len(arr) - k + 1):
            curSum += arr[L + k - 1]
            if (curSum / k) >= threshold:
                res += 1
            curSum -= arr[L]
        return res