BSTfromlinkedlist

Node <int> *   midelement(Node <int> * head)
{
    if(head->next == NULL)
    {
        return head ; 
    }
    Node <int> * slow = head ; 
    Node <int>  * fast = head ; 
    Node <int> * prev = NULL ; 
    while(fast != NULL && fast->next != NULL)
    {
        prev = slow ; 
        slow = slow->next ; 
       fast = fast->next->next ;
        
        
        
    }
    prev->next = NULL ; 
    return slow;
}


TreeNode<int>* sortedListToBST(Node<int>* head) 
{
    if(head == NULL)
    {
          
        return NULL;
        
    }
    if(head->next == NULL)
    {
         TreeNode<int>* root = new TreeNode <int>(head->data) ;
        return root ; 
    }
    Node <int> * mid = midelement(head) ;
    TreeNode<int>* root = new TreeNode <int>(mid->data) ;
    root->left =  sortedListToBST( head ) ;
    root->right =  sortedListToBST( mid->next)  ;
    return root ; 
    
	// Write your code here.
    
}