void linkedListInsert(Node *& headPtr,                     ListItemType newItem){   if ((headPtr == NULL) || (newItem < headPtr->item))   {  // base case: insert newItem at beginning      // of the linked list to which headPtr points      Node *newPtr = new Node;      newPtr->item = newItem;      newPtr->next = headPtr;      headPtr = newPtr;   }   else      linkedListInsert(headPtr->next,newItem);}  // end linkedListInsert