public class PowerExample2 {

    public static void main (String[] argv)
    {
        // We added a third parameter to track which call we're in.
        int p = power (3, 2, 0);
        System.out.println ( "3^2 = " + p);

        p = power (3, 4, 0);
        System.out.println ( "3^4 = " + p);

        p = power (2, 8, 0);
        System.out.println ( "2^8 = " + p);
    }


    static int power (int a, int b, int level)
    {
        // Print the "level", along with extra blanks.
        System.out.println ( makeBlanks(level) + "Level " + level + ": b=" + b );

        int p;
        
        if (b == 0) {
            p = 1;
        }
        else {
            p = a * power (a, b-1, level+1);
        }

        // Now the result.
        System.out.println ( makeBlanks(level) + "Level " + level + ": p=" + p );

        return p;
    }


    static String makeBlanks (int n)
    {
        String str = "";
        for (int i=0; i<n; i++) {
            str += "  ";
        }
        return str;
    }

}