In C#:

using System;

public class MaximumPathSum1 { public static void Main(string[] args) { int t = int.Parse(Console.ReadLine());

    while (t-- > 0)
    {
        int n = int.Parse(Console.ReadLine());
        int[][] arr = new int[n][];

        // Input values for each row of the array
        for (int i = 0; i < n; i++)
        {
            arr[i] = new int[i + 1]; // Initialize the array for the current row
            string[] values = Console.ReadLine().Split(' ');
            for (int j = 0; j <= i; j++)
            {
                arr[i][j] = int.Parse(values[j]); // Input the value for the current element
            }
        }

        // Call the max function and print the result
        Console.WriteLine(Max(arr));
    }
}

public static int Max(int[][] arr)
{
    int n = arr.Length;
    int[][] dp = new int[n][];
    for (int i = 0; i < n; i++)
    {
        dp[i] = new int[i + 1];
        for (int j = 0; j <= i; j++)
        {
            dp[i][j] = -1;
        }
    }
    return Recursive(0, 0, arr, n, dp);
}

private static int Recursive(int i, int j, int[][] arr, int n, int[][] dp)
{
    if (i < 0 || i >= n || j < 0 || j >= arr[i].Length)
    {
        return 0;
    }
    if (dp[i][j] != -1)
    {
        return dp[i][j];
    }
    int down = arr[i][j] + Recursive(i + 1, j, arr, n, dp);
    int right = arr[i][j] + Recursive(i + 1, j + 1, arr, n, dp);
    return dp[i][j] = Math.Max(down, right);
}

}