# 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]:
while root:
if root.val < val:
if root.right :
root = root.right
else:
return None
elif root.val > val:
if root.left:
root = root.left
else:
return None
else:
return root
return None