From bd77b3bb63445b8ab09d47a95ab7e4e07433b307 Mon Sep 17 00:00:00 2001
From: roylx <73628821+roylx@users.noreply.github.com>
Date: Wed, 12 Oct 2022 14:07:50 -0600
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0450.删除二叉搜索树中的节点.md 添加python3迭代法
---
 .../0450.删除二叉搜索树中的节点.md | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/problems/0450.删除二叉搜索树中的节点.md b/problems/0450.删除二叉搜索树中的节点.md
index 2d6d4ef2..541c8be4 100644
--- a/problems/0450.删除二叉搜索树中的节点.md
+++ b/problems/0450.删除二叉搜索树中的节点.md
@@ -344,6 +344,48 @@ class Solution:
         return root
 ```
 
+**迭代法**
+```python
+class Solution:
+    def deleteNode(self, root: Optional[TreeNode], key: int) -> Optional[TreeNode]:
+        # 找到节点后分两步，1. 把节点的左子树和右子树连起来，2. 把右子树跟父节点连起来
+        # root is None
+        if not root: return root
+        p = root
+        last = None
+        while p:
+            if p.val==key:
+                # 1. connect left to right
+                # right is not None -> left is None | left is not None
+                if p.right:
+                    if p.left:
+                        node = p.right
+                        while node.left:
+                            node = node.left
+                        node.left = p.left
+                    right = p.right
+                else:
+                # right is None -> right=left
+                    right = p.left
+                # 2. connect right to last
+                if last==None:
+                    root = right
+                elif last.val>key:
+                    last.left = right
+                else:
+                    last.right = right
+                # 3. return
+                break
+            else:
+                # Update last and continue
+                last = p
+                if p.val>key:
+                    p = p.left
+                else:
+                    p = p.right
+        return root
+```
+
 ## Go
 ```Go
 // 递归版本