void SSL::addByEngineType(Vehicle* vehicleIn)
{
		ListNode* temp = new ListNode();
		ListNode* newNode = new ListNode();
		newNode->setData(vehicleIn);

		while (true)
		{
			temp = head;
			if (head == NULL)//checks to see if the head empty
			{
				head = newNode;
				newNode->setPrevious(nullptr);
				newNode->setNext(nullptr);
				newNode->setSkip(nullptr);
				break;
			}
			else if (*(newNode->getData()->getEngine()) == *(head->getData()->getEngine()))  //compares the heads make to the inputed make
			{
				while (temp->getNext() != NULL) // cycles to the end of the data where the make is still the same
				{
					if (*(newNode->getData()->getEngine()) == *(temp->getNext()->getData()->getEngine()))
					{
						temp = temp->getNext(); // cycles to end of the head
					}
					else
					{
						break;
					}
				}
				temp->setNext(newNode);
				newNode->setPrevious(temp);
				newNode->setNext(head->getSkip()); // sets next to the next group
				break;
			}
			else
			{
				if (temp->getSkip() == nullptr)
				{
					temp->setSkip(newNode);//sets the new list to
					while (temp->getNext() != NULL)
					{
						temp = temp->getNext();
					}
					newNode->setNext(temp->getNext());
					temp->setNext(newNode);
					newNode->setPrevious(temp);

					break;
				}
				else
				{
					while (temp->getSkip() != nullptr)
					{
						if (*(newNode->getData()->getEngine()) != *(temp->getSkip()->getData()->getEngine()))
						{
							temp = temp->getSkip(); //cycles through the skips to get to the last one
						}
						else
						{
							break;
						}
					}
					if (*(newNode->getData()->getEngine()) == *(temp->getData()->getEngine()))
					{
						while (temp->getNext() != nullptr)
						{
							if (*(newNode->getData()->getEngine()) == *(temp->getData()->getEngine()))
							{
								temp = temp->getNext(); //cycles through the group to the last member of that group
							}
							else
							{
								break;
							}
						}
						temp->setNext(newNode);
						newNode->setPrevious(temp);
						newNode->setNext(nullptr);
					}
					if (*(newNode->getData()->getEngine()) != *(temp->getSkip()->getData()->getEngine()))
					{
						temp->setSkip(newNode);
					}
					while (temp->getNext() != nullptr)
					{
						temp = temp->getNext();
					}
					temp->setNext(newNode);
					newNode->setPrevious(temp);
					newNode->setNext(nullptr);
					break;
				}
			}
		}
	}