/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:

    void printVector(const vector<int>& vec) {
        for(int num : vec)
            std::cout << num << " ";

        std::cout << std::endl;
    }

    TreeNode* createTree(const vector<int>& nums, int start, int end) {

        if (start > end)
            return nullptr;

        int middle = start + (end - start) / 2;
        TreeNode* node = new TreeNode(nums[middle]);

        node->left = createTree(nums, start, middle - 1);
        node->right = createTree(nums, middle + 1, end);

        return node;
    }

    TreeNode* sortedArrayToBST(vector<int>& nums) {

        if (nums.size() == 0)
            return nullptr;

        return createTree(nums, 0, nums.size() - 1);
    }
};