Pascal Triangle help

[Magic101]

hey everyone i am new to Java that's why i need any help i can get.
i need to fill up the function Rows returns ragged array containing the first n rows of Pascal's triangle.
i tried playing around with it but considering i am totally new to this i have no idea if i am doing it right or how it should be implemented. I think i am doing way too much of what needs to be done.

can someone please take a look and based on what's given in the main function right now tell me what Rows should look like...

Code:

public class Pascal {
    public static int[][] Rows(int n){
    	int[][] pt = new int[n][];
    	for (int i = 0; i < n; i++) {
            pt[i] = new int[i + 1];                            // Construct row i.
            pt[i][0] = 1;                              // Leftmost value of row i.
            for (int j = 1; j < i; j++) {
              pt[i][j] = pt[i - 1][j - 1] + pt[i - 1][j];  // Sum 2 entries above.
            }
            pt[i][i] = 1;                             // Rightmost value of row i.
          }
          return pt;
    }

 
    public static void main(String[] args) {
        if (args.length != 1) {
          System.out.println("usage: java " + Pascal.class.getName() + " rows");
          System.exit(1);
        }
        int n = Integer.parseInt(args[0]);
        if (n > 0) {
          int[][] pascal = Rows(n);
          for (int[] row : pascal) {
    	for (int v : row) System.out.print(v + " ");
    	System.out.println("");
          }
        }
      }
}

when i try running this of course nothing gets printed except the usage:java message.

thanks a lot

[Zosden]

I would use recursion to generate the Fibonacci numbers then just print them out.

[Magic101]

Quote:

Originally Posted by Zosden

I would use recursion to generate the Fibonacci numbers then just print them out.

thanks for response... but would you mind actually showing me how it should be done.. i am clueless oh that part
Main function stays as it is other functions is the one that needs modification...

thanks.

[Zosden]

Heres a nice template for recursion

Code:

public <modifier> recusiveAlg(You need some sort of parameter)
{
     if(some sort of stopping criteria)
     {
         return something;
     }
     else
     {
         return recursiveAlg(your parameter - 1)
     }
}

Try to do this with Fibonacci numbers

hint: Fibonacci's numbers are the previous fib number + the one before the pervious fib number.

[Magic101]

Quote:

Originally Posted by Zosden

Heres a nice template for recursion

Code:

public <modifier> recusiveAlg(You need some sort of parameter)
{
     if(some sort of stopping criteria)
     {
         return something;
     }
     else
     {
         return recursiveAlg(your parameter - 1)
     }
}

Try to do this with Fibonacci numbers

hint: Fibonacci's numbers are the previous fib number + the one before the pervious fib number.

hmmm correct me if i'm wrong but isn't it already implemented in the main function?

Code:

if (n > 0) {
          int[][] pascal = Rows(n);
          for (int[] row : pascal) {
    	for (int v : row) System.out.print(v + " ");
    	System.out.println("");

all Rows has to do is to generate the array somehow to decide the row number...