Populating Next Right Pointers in Each Node II
Oct 28 '12
5299 / 13177
Follow up for problem "Populating Next Right Pointers in Each Node".
What if the given tree could be any binary tree? Would your previous solution still work?
Note:
- You may only use constant extra space.
For example,
Given the following binary tree,
1
/ \
2 3
/ \ \
4 5 7
After calling your function, the tree should look like:
1 -> NULL
/ \
2 -> 3 -> NULL
/ \ \
4-> 5 -> 7 -> NULL
/**
* Definition for binary tree with next pointer.
* public class TreeLinkNode {
* int val;
* TreeLinkNode left, right, next;
* TreeLinkNode(int x) { val = x; }
* }
*/
public class Solution {
public void connect(TreeLinkNode root) {
if(root==null) return ;
else{
root.next = null;
next(root);
}
}
public void next(TreeLinkNode root){
if(root==null) return ;
TreeLinkNode p1 = root;
TreeLinkNode p2=null,now;
while(p1!=null){
if(p1.left!=null){
if(now ==null){
p2 = p1.left;
now = p1.left;
}else{
now.next = p1.left;
now = now .next;
}
}
if(p1.right!=null){
if(now==null){
p2 = p1.right;
now = p1.right;
}else{
now.next = p1.right;
now = now.next;
}
}
p1 = p1.next;
}
if(now!=null)
now.next = null;
next(p2);
}
}