不知道变量范围是怎么规定的。改用返回值了。

Azureki · Dec 11, 2018 · 6403635 · 6403635
1 parent eb555c5
commit 6403635
Showing 1 changed file with 4 additions and 9 deletions.
diff --git a/Path Sum.py b/Path Sum.py
@@ -16,20 +16,15 @@ def hasPathSum(self, root, sum):
 
         def dfs(root, tar):
             if not root:
-                return
+                return False
             if root.val == tar and root.left is None and root.right is None:
-                global res
-                res = True
                 # print(23, res)
-                return
-            dfs(root.left, tar - root.val)
-            dfs(root.right, tar - root.val)
+                return True
+            return dfs(root.left, tar - root.val) or dfs(root.right, tar - root.val)
 
         if not root:
             return False
-        res = False
-        dfs(root, sum)
-        return res
+        return dfs(root, sum)
 
 
 root = TreeNode(5)