Convert Sorted Array to Binary Search Tree in python

问题链接

https://leetcode.com/explore/interview/card/top-interview-questions-easy/94/trees/631/

解题思路

递归查找中间值，并作为root节点，再找前后两段的中间值，作为左节点和右节点

代码

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def sortedArrayToBST(self, nums):
        """
        :type nums: List[int]
        :rtype: TreeNode
        """
        if len(nums) == 0:
            return None
        
        midx = len(nums)/2
        root = TreeNode(nums[midx])
        
        leftNode = self.sortedArrayToBST(nums[:midx])
        if leftNode:
            root.left = leftNode
        
        rightNode = self.sortedArrayToBST(nums[midx+1:])
        if rightNode:
            root.right = rightNode
        
        return root