题目链接

https://leetcode.cn/problems/search-in-a-binary-search-tree/

代码

递归法

# 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]:if not root or root.val == val:return rootif root.val < val:result = self.searchBST(root.right, val)if root.val > val:result = self.searchBST(root.left, val)return result

迭代

class Solution:def searchBST(self, root: Optional[TreeNode], val: int) -> Optional[TreeNode]:while root:if root.val < val: root = root.rightelif root.val > val: root = root.leftelse: return root