/* public class TreeLinkNode { int val; TreeLinkNode left = null; TreeLinkNode right = null; TreeLinkNode next = null; TreeLinkNode(int val) { this.val = val; } } */ import java.util.*; public class Solution { public TreeLinkNode GetNext(TreeLinkNode pNode) { if(pNode == null){ return null; } TreeLinkNode root = pNode; TreeLinkNode pNext = null; if(root.right != null){ root = root.right; while(root.left != null){ root = root.left; } return root; } while(root.next != null){ if(root.next.left == root){ return root.next; } root = root.next; } return null; } }