/**

  * 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:

     TreeNode* DFS(vector<int>& nums,int L,int R)

     {

         if(L>R)        return NULL;

         int mid=(L+R)>>;

         TreeNode* t=new TreeNode(nums[mid]);

         t->left=DFS(nums, L, mid-);

         t->right=DFS(nums, mid+, R);

         return t;

     }

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

         return DFS(nums,,nums.size()-);

     }

 };