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

        for r in range(k - 1, len(arr)):
            sum_ = 0
            for i in range(l, r + 1):
                sum_ += arr[i]

            if sum_ / k >= threshold:
                res += 1
            l += 1

        return res

class Solution:
    def numOfSubarrays(self, arr: List[int], k: int, threshold: int) -> int:
        prefix_sum = [0] * (len(arr) + 1)
        for i in range(len(arr)):
            prefix_sum[i + 1] += prefix_sum[i] + arr[i]

        res = l = 0
        for r in range(k - 1, len(arr)):
            sum_ = prefix_sum[r + 1] - prefix_sum[l]
            if sum_ / k >= threshold:
                res += 1
            l += 1

        return res

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

class Solution:
    def numOfSubarrays(self, arr: List[int], k: int, threshold: int) -> int:
        threshold *= k
        res = curSum = 0
        for R in range(len(arr)):
            curSum += arr[R]
            if R >= k - 1:
                res += curSum >= threshold
                curSum -= arr[R - k + 1]
        return res