14. 643. Maximum Average Subarray I

class Solution {
    public double findMaxAverage(int[] nums, int k) {
       
       int start=0;
       int end=0;
       int sum=0;
       int maxSum = Integer.MIN_VALUE;

       while(end<nums.length){
           sum =sum+nums[end++];

           while(start<end && end-start>k){
               sum-=nums[start++];

           }
        if(end-start==k)
         maxSum = Math.max(sum,maxSum);
       }
       double res = (double)maxSum/k;
       return res;
        
    }
}