新增 0235.二叉搜索树的最近公共祖先.md Python3迭代法

problems/0235.二叉搜索树的最近公共祖先.md

@@ -268,11 +268,22 @@ class Solution:
         if root.val < p.val and root.val < q.val:
             return self.lowestCommonAncestor(root.right, p, q)
         return root
- 
 ```
 
 迭代法：
+```python
+class Solution:
+    """二叉搜索树的最近公共祖先 迭代法"""
 
+    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
+        while True:
+            if root.val > p.val and root.val > q.val:
+                root = root.left
+            elif root.val < p.val and root.val < q.val:
+                root = root.right
+            else:
+                return root
+```
 
 ## Go