【LeetCode with Python】 Convert Sorted Array to Binary Search Tree

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原题页面：https://oj.leetcode.com/problems/convert-sorted-array-to-binary-search-tree/
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本文地址：http://blog.csdn.net/nerv3x3/article/details/39453279

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.

class Solution:        def doSortedArrayToBST(self, num, start, end):        if start > end:            return None        mid = start + (end - start) / 2        root = TreeNode(num[mid])        root.left = self.doSortedArrayToBST(num, start, mid - 1)        root.right = self.doSortedArrayToBST(num, mid + 1, end)        return root    # @param num, a list of integers    # @return a tree node    def sortedArrayToBST(self, num):        len_num = len(num)        if 0 == len_num:            return None        return self.doSortedArrayToBST(num, 0, len_num - 1)