Need Help: Recursive Code -- > Loop

[Wolfgang Obi]

Hello,

I'm having problems with following code segments....
'trying to make loop out of the first part...but something seems to be going wrong.

can anyone see my mistake.....?

thanks.
___________________________________________________________________

 static public void recu03(final int N) {
          char ziff = (char) (N%2 + '0'); 
          if (N < 0) {
          schritt01('-');
          recu03(-N);
          } else if (N == 0 || N == 1) { 
          schritt01(ziff);
          return;
          } else {
          recu03(N/2);
          schritt01(ziff);
          }
          } // recu03
  // -------------------------Loop--------------------------------- 
  static public  void iter03(final int N) {
             
                  int n = N;
                     if        (n <  0) {
                        schritt01('-');
                        n = -n;
                     } else if (n == 0 || n == 1) {                                   
char ziff = (char) (n);
                        schritt01(ziff);
                        return;
                     } else {
                                 while (n > 1) {
                                         n = n/2;
                                         char ziff = (char) (n%2 + '0'); 
                                        schritt01(ziff);
                                     }
                         }
          }// iter03
   

[ April 10, 2006: Message edited by: Wolfgang Obi ]

[ April 10, 2006: Message edited by: Wolfgang Obi ]
[ April 10, 2006: Message edited by: Wolfgang Obi ]

[marc weber]

What does the schritt01 method do? It's not defined in the posted code.

[marc weber]

Oh, I think I see. These methods are supposed to give a binary representation of the input int, right? And schritt01 basically concatenates a char to the output.

If you add the following test code...

static public void schritt01(char c) {
  System.out.print(c);  
}
  
public static void main(String[] args) {
  int i = Integer.parseInt(args[0]);
  System.out.println(Integer.toBinaryString(i));
  recu03(i);
  System.out.print("\n");
  iter03(i);
}

...and then run with a command line argument (for example, 1234567), you will see that recu03 does give the correct binary representation. However, iter03 is in reverse order and missing a digit.

H:\Java>java Tester 1234567
100101101011010000111
100101101011010000111
11000010110101101001 <== REVERSED AND MISSING DIGIT

That should suggest where the problem is.

[Wolfgang Obi]

thanks Marc!