Task

Build an   identity matrix   of a size known at run-time.



An identity matrix is a square matrix of size n × n,

where the diagonal elements are all 1s (ones),

and all the other elements are all 0s (zeroes).







I

n


=


[



1


0


0


⋯


0




0


1


0


⋯


0




0


0


1


⋯


0




⋮


⋮


⋮


⋱


⋮




0


0


0


⋯


1



]




{\displaystyle I_{n}={\begin{bmatrix}1&0&0&\cdots &0\\0&1&0&\cdots &0\\0&0&1&\cdots &0\\\vdots &\vdots &\vdots &\ddots &\vdots \\0&0&0&\cdots &1\\\end{bmatrix}}}





Related tasks

   Spiral matrix
   Zig-zag matrix 
   Ulam_spiral_(for_primes)


int main (string[] args) {
	if (args.length < 2) {
		print ("Please, input an integer > 0.\n");
		return 0;
	}
	var n = int.parse (args[1]);
	if (n <= 0) {
		print ("Please, input an integer > 0.\n");
		return 0;
	}
	int[,] array = new int[n, n];
	for (var i = 0; i < n; i ++) {
		for (var j = 0; j < n; j ++) {
			if (i == j) array[i,j] = 1;
			else array[i,j] = 0;
		}
	}
	for (var i = 0; i < n; i ++) {
		for (var j = 0; j < n; j ++) {
			print ("%d ", array[i,j]);
		}
		print ("\b\n");
	}
	return 0;
}