Update 0513.找树左下角的值.md

problems/0513.找树左下角的值.md

@@ -330,19 +330,24 @@ class Solution:
 #         self.right = right
 from collections import deque
 class Solution:
-    def findBottomLeftValue(self, root: Optional[TreeNode]) -> int:
-        queue = deque([root])
+    def findBottomLeftValue(self, root):
+        if root is None:
+            return 0
+        queue = deque()
+        queue.append(root)
+        result = 0
         while queue:
             size = len(queue)
-            leftmost = queue[0].val
             for i in range(size):
                 node = queue.popleft()
+                if i == 0:
+                    result = node.val
                 if node.left:
                     queue.append(node.left)
                 if node.right:
                     queue.append(node.right)
-            if not queue:
-                return leftmost
+        return result
+
 
 
 ```