Update 0102.二叉树的层序遍历.md

problems/0102.二叉树的层序遍历.md

@@ -1426,28 +1426,36 @@ public:
 python代码：
 
 ```python
+"""
+# Definition for a Node.
+class Node:
+    def __init__(self, val=None, children=None):
+        self.val = val
+        self.children = children
+"""
+
 class Solution:
-    """N叉树的层序遍历迭代法"""
-
     def levelOrder(self, root: 'Node') -> List[List[int]]:
-        results = []
         if not root:
-            return results
+            return []
 
-        from collections import deque
+        result = []
-        que = deque([root])
+        queue = collections.deque([root])
 
-        while que:
+        while queue:
-            result = []
+            level_size = len(queue)
-            for _ in range(len(que)):
+            level = []
-                cur = que.popleft()
-                result.append(cur.val)
-                # cur.children 是 Node 对象组成的列表，也可能为 None
-                if cur.children:
-                    que.extend(cur.children)
-            results.append(result)
 
-        return results
+            for _ in range(level_size):
+                node = queue.popleft()
+                level.append(node.val)
+
+                for child in node.children:
+                    queue.append(child)
+
+            result.append(level)
+
+        return result
 ```
 
 ```python