using System;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Max average of sub array");

        int[] nums = new int[] {1,12,-5,-6,50,3};

        Console.WriteLine(FindMaxAverage(nums, 4));

    }

​

    public static double FindMaxAverage(int[] nums, int k)

    {

        double maxSum = 0;

        double currentSum = 0;

        // Calculate the sum of the first k elements

        for (int i = 0; i < k; i++)

        {

            currentSum += nums[i];

        }

​

        maxSum = currentSum;

        // Use sliding window to calculate the sum of subarrays of length k

        for (int i = k; i < nums.Length; i++)

        {

            currentSum += nums[i] - nums[i - k];

            if (currentSum > maxSum)

            {

                maxSum = currentSum;

            }

        }

​

        return maxSum / k;

    }

​

    public static double FindMaxAverage11(int[] nums, int k)

    {

        double maxAvg = 0;

        double sumOfArray = 0;

        for (int i = 0; i < nums.Length; i++)

        {

            sumOfArray += nums[i];

        }

​

        if (k == nums.Length)

        {

            return sumOfArray / k;

        }

​

        int p1 = 0;

        int p2 = k - 1;

        double tmpMaxAvg = 0;

        while (p2 < nums.Length)

        {

            int pointerSum = nums[p1] + nums[p2];

            pointerSum = pointerSum < 0 ? pointerSum * -1 : pointerSum;

            tmpMaxAvg = (double)(sumOfArray - pointerSum) / (double)k;

            maxAvg = maxAvg > tmpMaxAvg ? maxAvg : tmpMaxAvg;

            p1++;

            p2++;

        }

​

        return maxAvg;

    }

}