Hi, I am trying to implement a simple binary tree class, but I don't know why my add method doesn't work. My TreeNode class is quite simple with only 3 fields, Comparable data, TreeNode lchild, rchild;public class Tree{
TreeNode current, root;
class TreeNode{
Comparable data;
TreeNode lchild, rchild;
TreeNode(TreeNode lc, Comparable d, TreeNode rc){
data=d;
lchild=lc;
rchild=rc;
}
}
/*void add(Comparable o){
if(root==null){
root = new TreeNode(null, o, null);
}
else
add(root, o);
}*/
Tree(){
root=current;
}
public void add(Comparable o){
if(root==null){
root=new TreeNode(null, o, null);
current = root;
return;
}
if(current==null){
current = new TreeNode(null, o, null);
current = root;
return;
}
else{
if(current.data.compareTo(o)>0){
current = current.lchild;
add(o);
}
else{
current = current.rchild;
add(o);
}
}
}
void traversal(TreeNode current){
if(current==null)
return;
else{
traversal(current.rchild);
System.out.println("preorder traversal:"+current.data);
traversal(current.lchild);
}
}
void printLeft(){
if(current==null){
current=root;
return;
}
else{
System.out.println("*.current.data="+current.data+" current.lchild="+current.lchild);
current=current.lchild;
printLeft();
}
}
public static void main(String[] args){
Tree t = new Tree();
for(int i=0; i<Integer.parseInt(args[0]); i++)
t.add(new Integer((int)(100*Math.random())));
t.printLeft();
}
}
