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

给一个数组arr, 求里面大小为k的sub array的平均值大于等于threshold的个数. running sum就可以.

class Solution {
    public int numOfSubarrays(int[] arr, int k, int threshold) {
        int count = 0;
        int s = 0;
        for(int i = 0; i <= arr.length; i++) {
            if(i < k){
                s += arr[i];
                continue;
            }
            if((double) s / k >= threshold)
                count++;
            if(i == arr.length)
                break;
            s -= arr[i - k];
            s += arr[i];
        }
        return count;
    }
}