LeetCode 108 Convert Sorted Array to Binary Search Tree（二分 + 递归建树）

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

题目大意：给出一个已经排好序的数组，构建一棵二叉搜索树。

解题思路：采用二分法，递归地构建BST。注意二分结束条件。

代码如下：

/** * Definition for a binary tree node. * struct TreeNode { *     int val; *     struct TreeNode *left; *     struct TreeNode *right; * }; */struct TreeNode* generateBST(int* nums, int left, int right) {    if(left >= right) return NULL;    int mid = (right - left) / 2 + left;    struct TreeNode* root = malloc(sizeof(struct TreeNode));    root->val = nums[mid];    root->left = generateBST(nums, left, mid);    root->right = generateBST(nums, mid + 1, right);    return root;}struct TreeNode* sortedArrayToBST(int* nums, int numsSize) {   return generateBST(nums, 0, numsSize);}