1008. Construct Binary Search Tree from Preorder Traversal (Medium) - TengnanYao/daily_leetcode GitHub Wiki

# 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 bstFromPreorder(self, preorder: List[int]) -> Optional[TreeNode]:
        if preorder:
            root = TreeNode(preorder[0])
            i = bisect.bisect(preorder, preorder[0])
            root.left = self.bstFromPreorder(preorder[1 : i])
            root.right = self.bstFromPreorder(preorder[i : ])
            return root