From f5a5cd882f3725cc56a95541bb738025e7b05d89 Mon Sep 17 00:00:00 2001
From: Wen Liang <wenslife@outlook.com>
Date: Thu, 2 Sep 2021 17:22:28 +0800
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---
 problems/0102.二叉树的层序遍历.md | 37 +++++++++++++----------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md
index a57a92aa..07708e5a 100644
--- a/problems/0102.二叉树的层序遍历.md
+++ b/problems/0102.二叉树的层序遍历.md
@@ -87,26 +87,31 @@ public:
 
 python代码：
 
-```python
+```python3
 class Solution:
+    """二叉树层序遍历迭代解法"""
+
     def levelOrder(self, root: TreeNode) -> List[List[int]]:
+        results = []
         if not root:
-            return []
+            return results
+        
+        from collections import deque
+        que = deque([root])
+        
+        while que:
+            size = len(que)
+            result = []
+            for _ in range(size):
+                cur = que.popleft()
+                result.append(cur.val)
+                if cur.left:
+                    que.append(cur.left)
+                if cur.right:
+                    que.append(cur.right)
+            results.append(result)
 
-        queue = [root]
-        out_list = []
-
-        while queue:
-            length = len(queue)  
-            in_list = []
-            for _ in range(length):
-                curnode = queue.pop(0)  # （默认移除列表最后一个元素）这里需要移除队列最头上的那个
-                in_list.append(curnode.val)
-                if curnode.left: queue.append(curnode.left)
-                if curnode.right: queue.append(curnode.right)
-            out_list.append(in_list)
-
-        return out_list
+        return results
 ```
 
 java: