test whether an integer M and another M are relative primes.

RelativePrime.java

public class RelativePrime
{
    public static int max(int M, int N)
    {
	return M >= N ? M : N;
    }
    public static int min(int M, int N)
    {
	return M <= N ? M : N;
    }
    public static boolean isRelativePrime(int M, int N)
    {
	if (M == 0 || N == 0)
	    return false;
	if ( M == 1 || N == 1)
	    return false;
	int k = min(M, N);

	for (int i = 2; i <= k; i++)
	    {
		if (M % i == 0 && N % i == 0)
		    return false;
	    }
	return true;
    }
    public static boolean[][] relativePrime(int N)
    {
	boolean[][] a = new boolean[N][N];
	for (int i = 0; i < N; i++)
	    for (int j = 0; j < N; j++)
		a[i][j] = isRelativePrime(i, j);
	return a;
    }
    public static void show(boolean[][] a)
    {
	int N = a.length;
	StdDraw.setXscale(-1, N);
	StdDraw.setYscale(-1, N);
	for (int i = 0; i < N; i++)
	    for (int j = 0; j < N; j++)
		{

		    if(a[i][j]) 
			{
			    StdDraw.setPenColor(StdDraw.BLACK);
			    
			}
		    else
			{
			    StdDraw.setPenColor(StdDraw.BLUE);
			}
		    StdDraw.filledSquare(j, N-1-i, .5);
		}
	
    }
    public static void main(String[] args)
    {
	int N = Integer.parseInt(args[0]);
	boolean[][] a = relativePrime(N);
	show(a);
    }
}