//In a square matrix if all the main diagonal elements are 1's and
//all the remaining elements are 0's is called an Identity Matrix.

using System;
class Exercise31
{
    public static void Main()
    {
        int[,] arr1 = new int[50,50];
        int i, j, r1,c1;
        Console.Write("\n\n Check whether a Given Matrix is an Identity Matrix :\n ");
        Console.Write("-----------------------------------------------------------\n");
        Console.Write(" Input the orders(2x2, 3x3, ...) of squere matrix : ");
        r1 = Convert.ToInt32(Console.ReadLine());
        c1=r1;
        Console.Write(" Input elements in the matrix :\n");
        for(i=0; i<r1; i++)
            {
                for(j=0; j<c1; j++)
                    {
                        Console.Write(" element - [{0}],[{1}] : ",i,j);
                        arr1[i,j] = Convert.ToInt32(Console.ReadLine());
                    }
            }
        Console.Write(" The matrix is :\n");
        for(i=0; i<r1; i++)
            {
                for(j=0; j<c1 ; j++)
                    Console.Write(" {0}  ",arr1[i,j]);
                Console.Write("\n");
            }
        for (i = 0; i < r1; i++)
            {
                for (j = 0; j < c1; j++)
                    {
                        if ((i == j && arr1[i, j] != 1) || (i != j && arr1[i, j] != 0))
                            {
                                goto label;
                            }
                    }
            }
        Console.WriteLine(" The matrix is an Identity Matrix.\n\n");
        return;
label:
        Console.WriteLine("\n The matrix is not an Identity Matrix\n\n");
    }
}