Update 0102.二叉树的层序遍历.md

problems/0102.二叉树的层序遍历.md

@@ -1761,22 +1761,37 @@ public:
 python代码：
 
 ```python
+# 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 largestValues(self, root: TreeNode) -> List[int]:
-        if root is None:
+        if not root:
             return []
-        queue = [root]
+
-        out_list = []
+        result = []
+        queue = collections.deque([root])
+
         while queue:
-            length = len(queue)
+            level_size = len(queue)
-            in_list = []
+            max_val = float('-inf')
-            for _ in range(length):
+
-                curnode = queue.pop(0)
+            for _ in range(level_size):
-                in_list.append(curnode.val)
+                node = queue.popleft()
-                if curnode.left: queue.append(curnode.left)
+                max_val = max(max_val, node.val)
-                if curnode.right: queue.append(curnode.right)
+
-            out_list.append(max(in_list))
+                if node.left:
-        return out_list
+                    queue.append(node.left)
+
+                if node.right:
+                    queue.append(node.right)
+
+            result.append(max_val)
+
+        return result
 ```
 
 java代码：