public class Solution
extends Object
700 - Search in a Binary Search Tree\.
Easy
You are given the `root` of a binary search tree (BST) and an integer `val`.
Find the node in the BST that the node's value equals `val` and return the subtree rooted with that node. If such a node does not exist, return `null`.
**Example 1:**
**Input:** root = [4,2,7,1,3], val = 2
**Output:** [2,1,3]
**Example 2:**
**Input:** root = [4,2,7,1,3], val = 5
**Output:** []
**Constraints:**
* The number of nodes in the tree is in the range `[1, 5000]`.
* 1 <= Node.val <= 107
* `root` is a binary search tree.
* 1 <= val <= 107