上三角行列を示す C# プログラム

if (i <= j)
   Console.Write(A[i, j] + "\t");
else
   Console.Write("0\t");

using System;
using System.Linq;
class Demo {
   static void Main() {
      int m, n, i, j;
      Console.Write("Enter number of rows and columns of the matrix ");
      m = Convert.ToInt16(Console.ReadLine());
      n = Convert.ToInt16(Console.ReadLine());
      int[,] A = new int[10, 10];
      Console.Write("Enter elements: ");
      for (i = 0; i < m; i++) {
         for (j = 0; j < n; j++) {
            A[i, j] = Convert.ToInt16(Console.ReadLine());
         }
      }
      Console.WriteLine("Upper Triangular Matrix ");
      for (i = 0; i < m; i++) {
         for (j = 0; j < n; j++) {
            Console.Write(A[i, j] + "\t");
         }
         Console.WriteLine();
      }
      for (i = 0; i < m; i++) {
         Console.Write("");
         for (j = 0; j < 3; j++) {
            if (i >= j)
               Console.Write(A[i, j] + "\t");
            else
               Console.Write("0\t");
         }
      }
      Console.ReadLine();
   }
}

Enter number of rows and columns of the matrix  
Enter elements:  
Upper Triangular Matrix