From 26f01c3ef9db64c890ae077c16a50544b990701f Mon Sep 17 00:00:00 2001
From: fw_qaq <82551626+fwqaaq@users.noreply.github.com>
Date: Fri, 9 Dec 2022 20:15:28 +0800
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?=
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---
 ...38.把二叉搜索树转换为累加树.md | 24 +++++++++++++++++++
 1 file changed, 24 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 36dbfa70..2f759d39 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
@@ -396,6 +396,30 @@ impl Solution {
 }
 ```
 
+迭代：
+
+```rust
+impl Solution {
+    pub fn convert_bst(root: Option<Rc<RefCell<TreeNode>>>) -> Option<Rc<RefCell<TreeNode>>> {
+        let mut cur = root.clone();
+        let mut stack = vec![];
+        let mut pre = 0;
+        while !stack.is_empty() || cur.is_some() {
+            while let Some(node) = cur {
+                cur = node.borrow().right.clone();
+                stack.push(node);
+            }
+            if let Some(node) = stack.pop() {
+                pre += node.borrow().val;
+                node.borrow_mut().val = pre;
+                cur = node.borrow().left.clone();
+            }
+        }
+        root
+    }
+}
+```
+
 
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