LeetCode Inorder Successor in BST

 1 /**
 2  * Definition for a binary tree node.
 3  * public class TreeNode {
 4  *     int val;
 5  *     TreeNode left;
 6  *     TreeNode right;
 7  *     TreeNode(int x) { val = x; }
 8  * }
 9  */
10 public class Solution {
11     public TreeNode inorderSuccessor(TreeNode root, TreeNode p) {
12         if(root == null || p == null){
13             return null;
14         }
15         TreeNode successor = null;
16         while(root != null){
17             if(p.val < root.val){
18                 successor = root;
19                 root = root.left;
20             }else{
21                 root = root.right;
22             }
23         }
24         return successor;
25     }
26 }