Update taurus09318976.py

Author: taurus09318976

construct-binary-tree-from-preorder-and-inorder-traversal/taurus09318976.py

@@ -56,6 +56,13 @@
 
 """
 
+# 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 buildTree(self, preorder, inorder):