Sliding Window - Maximum Average Subarray I

Given an integer array nums and integer k, find a contiguous subarray of length k that has the maximum average. Return this maximum average.

Input: nums=[1,12,-5,-6,50,3], k=4 → Output: 12.75

Input: nums=[5], k=1 → Output: 5.0

Use a fixed-size sliding window of size k. Compute the initial sum of first k elements, then slide the window by subtracting the leftmost element and adding the new rightmost element.

Compute sum of first k elements.
Slide from index k to n-1: add nums[i], subtract nums[i-k].
Track maximum sum throughout.
Return maxSum / k as double.

class Solution { public double findMaxAverage(int[] nums, int k) { int sum = 0; for (int i = 0; i < k; i++) sum += nums[i]; int maxSum = sum; for (int i = k; i < nums.length; i++) { sum += nums[i] - nums[i - k]; maxSum = Math.max(maxSum, sum); } return (double) maxSum / k; } }

Time Complexity: O(N)
Space Complexity: O(1)