Update 0102.二叉树的层序遍历.md

problems/0102.二叉树的层序遍历.md

@@ -512,27 +512,29 @@ python代码：
 class Solution:
     """二叉树层序遍历II迭代解法"""
 
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
     def levelOrderBottom(self, root: TreeNode) -> List[List[int]]:
-        results = []
         if not root:
-            return results
-
-        from collections import deque
-        que = deque([root])
-
-        while que:
+            return []
+        queue = collections.deque([root])
         result = []
-            for _ in range(len(que)):
-                cur = que.popleft()
-                result.append(cur.val)
+        while queue:
+            level = []
+            for _ in range(len(queue)):
+                cur = queue.popleft()
+                level.append(cur.val)
                 if cur.left:
-                    que.append(cur.left)
+                    queue.append(cur.left)
                 if cur.right:
-                    que.append(cur.right)
-            results.append(result)
-
-        results.reverse()
-        return results
+                    queue.append(cur.right)
+            result.append(level)
+        return result[::-1]
 ```
 
 Java：