<p>You are given the <code>root</code> of a binary search tree (BST) and an integer <code>val</code>.</p>

<p>Find the node in the BST that the node&#39;s value equals <code>val</code> and return the subtree rooted with that node. If such a node does not exist, return <code>null</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/01/12/tree1.jpg" style="width: 422px; height: 302px;" />
<pre>
<strong>Input:</strong> root = [4,2,7,1,3], val = 2
<strong>Output:</strong> [2,1,3]
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/01/12/tree2.jpg" style="width: 422px; height: 302px;" />
<pre>
<strong>Input:</strong> root = [4,2,7,1,3], val = 5
<strong>Output:</strong> []
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The number of nodes in the tree is in the range <code>[1, 5000]</code>.</li>
	<li><code>1 &lt;= Node.val &lt;= 10<sup>7</sup></code></li>
	<li><code>root</code> is a binary search tree.</li>
	<li><code>1 &lt;= val &lt;= 10<sup>7</sup></code></li>
</ul>

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def searchBST(self, root: Optional[TreeNode], val: int) -> Optional[TreeNode]:
        node = root
        while node:
            if node.val == val:
                return node
            if node.val < val:
                node = node.right
            else:
                node = node.left
        return None
18000