递归与二叉树_leetcode108

# 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
        """

        size = len(nums)

        if size == 0:
            return None

        if size == 1:
            return  TreeNode(nums[0])

        mid = size / 2

        root = TreeNode(nums[mid])
        root.left = self.sortedArrayToBST(nums[0:mid])
        root.right = self.sortedArrayToBST(nums[mid+1:size])

        return root