문제 설명

Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.

A height-balanced binary tree is a binary tree in which the depth of the two subtrees of every node never differs by more than one.

코드

# 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 recursion(self,nums:List[int],start:int,end:int)->Optional[TreeNode]:
        if start>end:
            return None
        else:
            mid=(start+end)//2
            node=TreeNode(nums[mid])
            node.left=self.recursion(nums,start,mid-1)
            node.right=self.recursion(nums,mid+1,end)
            return node
        
    def sortedArrayToBST(self, nums: List[int]) -> Optional[TreeNode]:
        
        return self.recursion(nums,0,len(nums)-1)