LeetCode: Inorder Successor in Binary Search Tree

// Given a binary search tree and a node in it, find the in-order successor of that node in the BST.

// Note: If the given node has no in-order successor in the tree, return null.

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class InorderSuccessorInBST {
    public TreeNode inorderSuccessor(TreeNode root, TreeNode p) {
        TreeNode successor = null;
     
        while(root != null) {
            if(p.val < root.val) {
                successor = root;
                root = root.left;
            } else {
                root = root.right;
            }
        }
     
        return successor;
    }
}