643. Maximum Average Subarray I

Source

Solution :

class Solution {
    public double findMaxAverage(int[] nums, int k) {
        if (k > nums.length) return 0.0;
 
        int begin = 0, end = 0;
        double sum = 0.0;
        double maxAverage = Double.NEGATIVE_INFINITY;
 
        while (end < nums.length) {
            sum += nums[end];
			//As soon as the window size is k find the avg and store in Max Average.
            if (end - begin + 1 == k) {
			    double tempAvg = sum/k;
                maxAverage = Math.max(maxAverage, tempAvg);
                sum -= nums[begin];
                begin++;
            }
            end++;
        }
 
        return maxAverage;
    }
}