Happy Thanksgiving! I am happy to have solved this without looking up a solution. However, I did have to review traversals.

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Solution

from collections import deque

# 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: List[int], inorder: List[int]) -> Optional[TreeNode]:
        top = deque(preorder)
        bottom = deque(inorder)
        nodes = []
        seen = set()

        root = parent = TreeNode()
        while top:
            parent.right = TreeNode(top.popleft())
            left = parent.right
            seen.add(left.val)
            nodes.append(left)
            while left.val != bottom[0]:
                left.left = TreeNode(top.popleft())
                left = left.left
                seen.add(left.val)
                nodes.append(left)
            while bottom and bottom[0] in seen:
                bottom.popleft()
                parent = nodes.pop()
            
        return root.right

Time complexity is O(n) = n and space complexity is O(n) due to set and deques.