DSA using JavaScript

Time Complexity: O(n * k)
Space Complexity: O(1)

Sliding Window

function findMaxAverage(nums, k) {
    let maxAvg = -Infinity;

    for (let i = 0; i <= nums.length - k; i++) {
        let sum = 0;
        for (let j = 0; j < k; j++) {
            sum += nums[i + j];
        }
        let avg = sum / k;
        maxAvg = Math.max(maxAvg, avg);
    }

    return maxAvg;
}
const nums = [1, 12, -5, -6, 50, 3];
const k = 4;
console.log(findMaxAverage(nums, k));  // Output: 12.75

function findMaxAverage(nums, k) {
    let windowSum = 0;

    // Calculate initial window sum
    for (let i = 0; i < k; i++) {
        windowSum += nums[i];
    }

    let maxSum = windowSum;

    // Slide the window
    for (let i = k; i < nums.length; i++) {
        windowSum = windowSum - nums[i - k] + nums[i];
        maxSum = Math.max(maxSum, windowSum);
    }

    return maxSum / k;
}
const nums = [1, 12, -5, -6, 50, 3];
const k = 4;
console.log(findMaxAverage(nums, k));  // Output: 12.75