Maximum Average Subarray I

Problem

Given an integer array nums and integer k, find a contiguous subarray of exactly length k that has the maximum average value, and return that value. Example: nums=[1,12,-5,-6,50,3], k=4 → 12.75 (the subarray [12,-5,-6,50] has average 51/4 = 12.75).

Constraints

• ›1 ≤ k ≤ n ≤ 10⁵
• ›-10⁴ ≤ nums[i] ≤ 10⁴