leetcode106

 1 class Solution:
 2     def buildTree(self, inorder: List[int], postorder: List[int]) -> TreeNode:
 3         if len(postorder)==0 or len(inorder)==0:
 4             return None
 5 
 6         val = postorder[-1]
 7         t = TreeNode(val)
 8         index = inorder.index(val)
 9         t.left = self.buildTree(inorder[:index],postorder[:index])
10         t.right = self.buildTree(inorder[index+1:],postorder[index:-1])
11         return t