import java.util.*; /* public class TreeLinkNode { int val; TreeLinkNode left = null; TreeLinkNode right = null; TreeLinkNode next = null; TreeLinkNode(int val) { this.val = val; } } */ public class Solution { TreeLinkNode resNode = null; TreeLinkNode preNode = null; public TreeLinkNode GetNext(TreeLinkNode pNode) { TreeLinkNode root = pNode; while(root.next != null){ root = root.next; } inOrder(root,pNode); return resNode; } private void inOrder(TreeLinkNode root,TreeLinkNode pNode){ if(root == null){ return; } inOrder(root.left,pNode); if(preNode!=null &&preNode == pNode){ resNode = root; } preNode = root; inOrder(root.right,pNode); } }