From daa5417db9ef711d219ca8e201c6dd0cd57c9a20 Mon Sep 17 00:00:00 2001
From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com>
Date: Tue, 23 May 2023 21:11:37 -0500
Subject: [PATCH] =?UTF-8?q?Update=200236.=E4=BA=8C=E5=8F=89=E6=A0=91?=
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---
 .../0236.二叉树的最近公共祖先.md    | 45 +++++++++++++------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/problems/0236.二叉树的最近公共祖先.md b/problems/0236.二叉树的最近公共祖先.md
index 33201def..0ebd5566 100644
--- a/problems/0236.二叉树的最近公共祖先.md
+++ b/problems/0236.二叉树的最近公共祖先.md
@@ -274,25 +274,44 @@ class Solution {
 ```
 
 ## Python 
-
+递归法（版本一）
 ```python
 class Solution:
-    """二叉树的最近公共祖先 递归法"""
-
-    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
-        if not root or root == p or root == q:
+    def lowestCommonAncestor(self, root, p, q):
+        if root == q or root == p or root is None:
             return root
-        
+
         left = self.lowestCommonAncestor(root.left, p, q)
         right = self.lowestCommonAncestor(root.right, p, q)
-        
-        if left and right:
-            return root
-        if left:
-            return left
-        return right
-```
 
+        if left is not None and right is not None:
+            return root
+
+        if left is None and right is not None:
+            return right
+        elif left is not None and right is None:
+            return left
+        else: 
+            return None
+```
+递归法（版本二）精简
+```python
+class Solution:
+    def lowestCommonAncestor(self, root, p, q):
+        if root == q or root == p or root is None:
+            return root
+
+        left = self.lowestCommonAncestor(root.left, p, q)
+        right = self.lowestCommonAncestor(root.right, p, q)
+
+        if left is not None and right is not None:
+            return root
+
+        if left is None:
+            return right
+        return left
+
+```
 ## Go 
 
 ```Go