题目：

题解：

class Solution:def sortedArrayToBST(self, nums: List[int]) -> TreeNode:def helper(left, right):if left > right:return None# 选择任意一个中间位置数字作为根节点mid = (left + right + randint(0, 1)) // 2root = TreeNode(nums[mid])root.left = helper(left, mid - 1)root.right = helper(mid + 1, right)return rootreturn helper(0, len(nums) - 1)