From 6943358d8f75b4c189bcedaa5b79d5c0b0a93c2a Mon Sep 17 00:00:00 2001
From: ZerenZhang2022 <118794589+ZerenZhang2022@users.noreply.github.com>
Date: Fri, 31 Mar 2023 21:58:27 -0400
Subject: [PATCH] =?UTF-8?q?Update=200538.=E6=8A=8A=E4=BA=8C=E5=8F=89?=
 =?UTF-8?q?=E6=90=9C=E7=B4=A2=E6=A0=91=E8=BD=AC=E6=8D=A2=E4=B8=BA=E7=B4=AF?=
 =?UTF-8?q?=E5=8A=A0=E6=A0=91.md?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

增加 python 迭代法
---
 ...38.把二叉搜索树转换为累加树.md | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/problems/0538.把二叉搜索树转换为累加树.md b/problems/0538.把二叉搜索树转换为累加树.md
index 29b21840..ad5310e1 100644
--- a/problems/0538.把二叉搜索树转换为累加树.md
+++ b/problems/0538.把二叉搜索树转换为累加树.md
@@ -234,6 +234,26 @@ class Solution:
         return root 
         
 ```
+**迭代**
+```python
+class Solution:
+    def convertBST(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
+        if not root: return root
+        stack = []
+        result = []
+        cur = root
+        pre = 0
+        while cur or stack:
+            if cur:
+                stack.append(cur)
+                cur = cur.right
+            else: 
+                cur = stack.pop()
+                cur.val+= pre
+                pre = cur.val
+                cur =cur.left
+        return root
+```            
 
 ## Go