Help with recursion

[Jay Kamdar]

I have this program to code but my output is only different because some of the lines have too little spaces before them.

Here is the problem
A Fractal Pattern
Examine this pattern of asterisks and blanks, and write a recursive function that can generate patterns such as this:

*
* * 
  *
* * * *
    *
    * *
      *
* * * * * * * *
        *
        * *
          *
        * * * *
            *
            * *
              *

With recursive thinking, the function needs only seven or eight lines of code (including two recursive calls). Your prototype should look like this:

String pattern(String outs, int n, int i);
// Precondition: n is a power of 2 greater than zero.
// Postcondition: A pattern based on the above example has been
// printed to the String outs. The longest line of the pattern has
// n stars beginning in column i of the output. For example,
// The above pattern is produced by the call pattern(out, 8, 0).

Hints: You do not need to check the precondition. Think about how the pattern is a fractal. Can you find two smaller versions of the pattern within the large pattern? Here is some code that may be useful within your function:

// A loop to print exactly i spaces:
for (k = 0; k < i; k++) outs += ' ';

// A loop to print n asterisks, each one followed by a space:
for (k = 0; k < n; k++) outs += "* ";


Here is my code

public static String pattern(String outs, int n, int i)
{      
    int na = (int)(Math.log(n)/Math.log(2));    
    if (na == 0)
    {
            for (int k = 0; k < i; k++) outs += ' ';
            for (int k = 0; k < n; k++) outs += "* "; 
            return outs+= '\n';   
        }
        else
        {
                outs = pattern(outs,(int)(Math.pow(2.0,na - 1)),i);
                for (int k = 0; k < i; k++) outs += ' ';
                for (int k = 0; k < n; k++) outs += "* "; 
                outs+= '\n'; 
                i+= na * 2;
                return outs = pattern(outs,(int)(Math.pow(2.0,na - 1)),i);  
        }
}

My output looks like this

*
* * 
  *
* * * *
    *
    * *
      *
* * * * * * * *
      *
      * *
        *
      * * * *
          *
          * *
            *

[ November 25, 2005: Message edited by: Marilyn de Queiroz ]

[Chad Clites]

EDIT: NeverMind.. now I see how your output is different from the required output. It looks like you need to somehow add an extra space in there...
[ November 27, 2005: Message edited by: C Clites ]