108-Convert Sorted Array to Binary Search Tree.cpp

/**
 * 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* sortedArrayToBST(vector<int>& nums,int start,int end)
    {
        if(start>end)
            return NULL;
        int mid=(start+end)/2;
        TreeNode* Node=new TreeNode(nums[mid]);
        if(start==end)
            return Node;
        Node->left=sortedArrayToBST(nums,start,mid-1);
        Node->right=sortedArrayToBST(nums,mid+1,end);
        return Node;
    }
    TreeNode* sortedArrayToBST(vector<int>& nums)
    {
       return sortedArrayToBST(nums,0,nums.size()-1);
    }
};