# Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution: def sortedArrayToBST(self, nums: List[int]) -> TreeNode: def dfs(l: int, r: int) -> TreeNode: if l > r: return None mid = (l + r) >> 1 return TreeNode(nums[mid], dfs(l, mid - 1), dfs(mid + 1, r)) return dfs(0, len(nums) - 1)