using System;
public class Program
{
//Given an array of integers of size ‘n’.
//Our aim is to calculate the maximum sum of ‘k’
//consecutive elements in the array.
//Input : arr[] = { 100, 200, 300, 400}
//k = 2
//Output : 700
//Input : arr[] = {1, 4, 2, 10, 23, 3, 1, 0, 20}
//k = 4
//Output : 39
//We get maximum sum by adding subarray {4, 2, 10, 23}
//of size 4.
//Input : arr[] = {2, 3}
//k = 3
//Output: Invalid
//There is no subarray of size 3 as size of whole
//array is 2.
// Driver code
public static void Main()
int[] arr = { 1, 4, 2, 10, 2, 3, 1, 0, 20 };
int k = 4;
int n = arr.Length;
Console.WriteLine(MaxSum(arr, n, k));
}
// Returns maximum sum in a
// subarray of size k.
public static int MaxSum(int[] arr, int n, int k)
int max_sum = int.MinValue;
//Write Code
return max_sum;