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;
}
}