struct LinkedList {
      LinkedList* next;
      int data;
   }

   void reverseLL(linkedList* ll){
      if (ll==NULL) return NULL;
      LinkedList* newList;
      prev = NULL;
      for (;;) {
         newList = malloc(LinkedList);
         newList->data = ll->data;
         newList->next = prev;
         if (ll->next==NULL) break;
         prev = newList;
         ll = ll->next;
      }
      return newList;
   }