二叉树的下一个节点

/*
public class TreeLinkNode {
int val;
TreeLinkNode left = null;
TreeLinkNode right = null;
TreeLinkNode next = null;

TreeLinkNode(int val) {
this.val = val;
}
}
*/
public class Solution {
public TreeLinkNode GetNext(TreeLinkNode pNode)
{
if(pNode==null){
return null;
}
TreeLinkNode pNext=null;
if(pNode.right!=null){
TreeLinkNode pRight=pNode.right;
while(pRight.left!=null){
pRight=pRight.left;
}
pNext=pRight;
}else if(pNode.next!=null){
TreeLinkNode pCur=pNode;
TreeLinkNode parent=pNode.next;
while(parent!=null&&pCur!=parent.left){
pCur=parent;
parent=pCur.next;
}
pNext=parent;
}
return pNext;
}
}