Help on resetting my own linked list.

Question

I got a Binary tree project, but to get things started, i decided to put all the elements into a LinkedList first.
Anyway, it seems i forgot how to go back to the root of my linkedList. I can traverse through the LinkedList, but it seems that whenever I try to call it again, it's already at the end of the List. My linkedList consist of a Integer, and a the next Node is called "left" atm.
Here's my code:
class MyTree { //class definition
     class Node {
          int data;
          Node left;
          Node right;
private Node root;
private int [] rdata;
Node m = new Node();
BufferedReader in;
   public void generate(int n, int range){
          Random r = new Random();
          rdata  = new int[n];
                  for (int i = 0; i<n; i++) {
                        rdata[i] = r.nextInt(range);
          Node b = new Node();
          for (int j = 0; j<n; j++){ 
               b.data = rdata[j];
               m.left = b;
               m = m.left;
               System.out.println("m.data " + m.data);
               Now whenever I try to call it back again, It would only print the last integer in the LinkedList, so I had to use an array to set it up it again basically.
     public void show() {
               Node b = new Node();
               for (int j = 0; j<rdata.length; j++){ 
               b.data = rdata[j];
               m.left = b;
               m = m.left;
               System.out.println("m.data " + m.data);
     }I'll like to traverse through the list again without setting up the linked list every time.
Thanks in Advance.
Message was edited by:
Vertix
Message was edited by:
Vertix
Message was edited by:
Vertix
Message was edited by:
Vertix
Message was edited by:
Vertix

Answer 1

Well, I tried to remove Node b, and just use the Node
m to set up my LinkedList.[ code snipped ]
But it's giving NullPointerExceptions everytime I try to run it. I already
created a Node m at the begging, so I don't see where it's getting the
nullpointer.That's not how you should create that list. You need a new node per
element in the rdata[] array. There are two possible states:
1) there isn't a list yet, i.e. the 'root' element equals null
2) there's a list already and 'm' points to the last element of the list.
This is how you do it:m= root; // both are null; see 1)
for (int i= 0; i < rdata.length; i++) { // build the list
   Node b= new Node(); // build a new node
   b.data= rdata;
if (root == null) // first list element?
root= b;
else // no, hookup to last element
m.left= b;
m= b; // m points to last element
kind regards,
Jos