(109)Method1- Convert Sorted List to Binary Search Tree

class Solution 
{
public:
    TreeNode* tree(vector<int>nums , int low , int high)
    {
        if(low>high)    return nullptr;
        int mid = low+(high-low)/2;
        TreeNode *root = new TreeNode(nums[mid]);
        root->left = tree(nums , low,mid-1);
        root->right = tree(nums , mid+1 , high);
        return root;
    }
    
    TreeNode* sortedListToBST(ListNode* head) 
    {
        if(!head)   return nullptr;
        vector<int>res;
        while(head)
        {
            res.push_back(head->val);
            head = head->next;
        }
        TreeNode* ans = tree(res,0,res.size()-1);
        return ans;
    }
};