Leetcode 643 Maximum Average Subarray I

Leetcode 643 Maximum Average Subarray I

class Solution {
public:
double findMaxAverage(vector<int>& nums, int k) {
int size = nums.size();
double sum = 0;
double maxSum = 0;//ATTENTION double~
for(int i = 0;i < size;i ++)
{
if(i < k)
{
sum += nums[i];
maxSum = sum;
}
else
{
sum += nums[i];
sum -= nums[i-k];//add the nums[i] ,minor nums[i - k],slide the window
maxSum = max(maxSum,sum);
}
}
return maxSum / k;

}
};