105. Construct Binary Tree from Preorder and Inorder Traversal

class Solution:
    def buildTree(self, preorder: List[int], inorder: List[int]) -> TreeNode:
        if not preorder and not inorder:
            return
    
        root = TreeNode(preorder[0])
        mid = inorder.index(preorder[0])

        root.left = self.buildTree(preorder[1:mid+1], inorder[:mid])
        root.right = self.buildTree(preorder[mid+1:], inorder[mid+1:])

        return root