From dd58553088514af1a1a019fb9e6d4b2e41b0aeb5 Mon Sep 17 00:00:00 2001
From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com>
Date: Wed, 3 May 2023 19:26:39 -0500
Subject: [PATCH] =?UTF-8?q?Update=20=E4=BA=8C=E5=8F=89=E6=A0=91=E7=9A=84?=
 =?UTF-8?q?=E9=80=92=E5=BD=92=E9=81=8D=E5=8E=86.md?=
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---
 problems/二叉树的递归遍历.md | 53 +++++++++++++---------------
 1 file changed, 24 insertions(+), 29 deletions(-)

diff --git a/problems/二叉树的递归遍历.md b/problems/二叉树的递归遍历.md
index 5a9a670a..8d5a5985 100644
--- a/problems/二叉树的递归遍历.md
+++ b/problems/二叉树的递归遍历.md
@@ -174,50 +174,45 @@ class Solution {
 Python：
 ```python
 # 前序遍历-递归-LC144_二叉树的前序遍历
+# 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 preorderTraversal(self, root: TreeNode) -> List[int]:
-        # 保存结果
-        result = []
-        
-        def traversal(root: TreeNode):
-            if root == None:
-                return
-            result.append(root.val) # 前序
-            traversal(root.left)    # 左
-            traversal(root.right)   # 右
+        if not root:
+            return []
+
+        left = self.preorderTraversal(root.left)
+        right = self.preorderTraversal(root.right)
+
+        return  [root.val] + left +  right
 
-        traversal(root)
-        return result
 
 # 中序遍历-递归-LC94_二叉树的中序遍历
 class Solution:
     def inorderTraversal(self, root: TreeNode) -> List[int]:
-        result = []
+        if root is None:
+            return []
 
-        def traversal(root: TreeNode):
-            if root == None:
-                return
-            traversal(root.left)    # 左
-            result.append(root.val) # 中序
-            traversal(root.right)   # 右
+        left = self.inorderTraversal(root.left)
+        right = self.inorderTraversal(root.right)
 
-        traversal(root)
-        return result
+        return left + [root.val] + right
 
 # 后序遍历-递归-LC145_二叉树的后序遍历
 class Solution:
     def postorderTraversal(self, root: TreeNode) -> List[int]:
-        result = []
+        if not root:
+            return []
 
-        def traversal(root: TreeNode):
-            if root == None:
-                return
-            traversal(root.left)    # 左
-            traversal(root.right)   # 右
-            result.append(root.val) # 后序
+        left = self.postorderTraversal(root.left)
+        right = self.postorderTraversal(root.right)
 
-        traversal(root)
-        return result
+        return left + right + [root.val]
 ```
 
 Go：