题目

convert-sorted-array-to-binary-search-tree

2. 算法

* 二分查找

3. 代码

```

###* 递归


```cpp
class Solution {
public:
    TreeNode *sortedArrayToBST(vector<int> &num) {
        return sortedArrayToBST(num, 0 , num.size() - 1);
    }
    TreeNode *sortedArrayToBST(vector<int> &num, int left, int right) {
        if (left > right) return NULL;
        int mid = (left + right) / 2;
        TreeNode *cur = new TreeNode(num[mid]);
        cur->left = sortedArrayToBST(num, left, mid - 1);
        cur->right = sortedArrayToBST(num, mid + 1, right);
        return cur;
    }
};