Merge pull request #3 from AnandBaburajan/patch-1

flonle · web-flow · commit 515f1bf750b0 · 2022-07-27T16:28:36.000+02:00
543-Diameter-of-Binary-Tree.py: Use nonlocal res instead of using a list
diff --git a/python/543-Diameter-of-Binary-Tree.py b/python/543-Diameter-of-Binary-Tree.py
@@ -5,17 +5,19 @@
 #         self.left = left
 #         self.right = right
 class Solution:
-    def diameterOfBinaryTree(self, root: TreeNode) -> int:
-        res = [0]
+    def diameterOfBinaryTree(self, root: Optional[TreeNode]) -> int:
+        res = 0
 
         def dfs(root):
+            nonlocal res
+
             if not root:
                 return 0
             left = dfs(root.left)
             right = dfs(root.right)
-            res[0] = max(res[0], left + right)
+            res = max(res, left + right)
 
             return 1 + max(left, right)
 
         dfs(root)
-        return res[0]
+        return res
