public class Triangle {

    public static void main (String[] argv)
    {
        int[][] A = {
            {1},
            {2, 1},
            {3, 2, 1},
            {4, 3, 2, 1},
            {5, 4, 3, 2, 1}
        };
        print (A);
    }

    static void print (int[][] A)
    {
        // The number of rows is still A.length.
        for (int i=0; i<A.length; i++) {

            System.out.print ("Row i=" + i + " has " + A[i].length + " elements: ");

            // Note: we must use A[i].length, since they are all different.
            for (int j=0; j<A[i].length; j++) {
                System.out.print (" " + A[i][j]);
            }

            System.out.println ();
        }
    }
    

}