public class Solution
extends Object
643 - Maximum Average Subarray I\.
Easy
You are given an integer array `nums` consisting of `n` elements, and an integer `k`.
Find a contiguous subarray whose **length is equal to** `k` that has the maximum average value and return _this value_. Any answer with a calculation error less than 10-5 will be accepted.
**Example 1:**
**Input:** nums = [1,12,-5,-6,50,3], k = 4
**Output:** 12.75000
**Explanation:** Maximum average is (12 - 5 - 6 + 50) / 4 = 51 / 4 = 12.75
**Example 2:**
**Input:** nums = [5], k = 1
**Output:** 5.00000
**Constraints:**
* `n == nums.length`
* 1 <= k <= n <= 105
* -104 <= nums[i] <= 104