def buildTreeRecu(self, lookup, postorder, inorder, post_end, in_start, in_end):
        if in_start == in_end:
            return None
        node = TreeNode(postorder[post_end - 1])
        i = lookup[postorder[post_end - 1]]
        node.left = self.buildTreeRecu(lookup, postorder, inorder, post_end - 1 - (i - 1 - in_end), in_start, i)
        node.right = self.buildTreeRecu(lookup, postorder, inorder, post_end - 1, i + 1, in_end)
        return node
dataset/ETHPy150Open kamyu104/LeetCode/Python/construct-binary-tree-from-inorder-and-postorder-traversal.py/Solution.buildTreeRecu/swapped operands of `-`