Hadamard matrix

Hadamar.java

public class Hadamard
{
    public static void main(String[] args)
    {
	int N = Integer.parseInt(args[0]);
	boolean[][] H = new boolean[N][N];
	H[0][0] = true;
	for(int n = 1; n < N; n += n)
	    {
		for(int i = 0; i < n; i++)
		    for(int j = 0; j < n; j++)
			{
			    H[i+n][j] = H[i][j];
			    H[i][j+n] = H[i][j];
			    H[i+n][j+n] = !H[i][j];
			}
	    }
	for(int i = 0; i < N; i++)
	    {
		for(int j = 0; j < N; j++)
		    {
			if(H[i][j]) System.out.print("* ");
			else        System.out.print(". ");
		    }
		System.out.println();
	    }
    }

}