python-leetcode面试题解之第108题将有序数组转换为二叉搜索树-题解.zip

# 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 # """ # # Recursion with slicing # if not nums: # return None # mid = len(nums) / 2 # root = TreeNode(nums[mid]) # root.left = self.sortedArrayToBST(nums[:mid]) # root.right = self.sortedArrayToBST(nums[mid + 1:]) # return root def sortedArrayToBST(self, nums): # Recursion with index return self.getHelper(nums, 0, len(nums) - 1) def getHelper(self, nums, start, end): if start > end: return None mid = (start + end) / 2 node = TreeNode(nums[mid]) node.left = self.getHelper(nums, start, mid - 1) node.right = self.getHelper(nums, mid + 1, end) return node