I am having trouble coming up with a way to come up with this method.

Directions:

Your add() method in the OrderedList is replacing the add() method in the ListNodePlus class. You have access to that class, take a look at the code there. Specifically, this method:

public void add(int idx, E it) { if (idx < 0 || idx > countOfElements) { return; } Node curr = head.getNext(); Node prev = head; for (int i = 0; i < idx; i++) { prev = curr; curr = curr.getNext(); } prev.setNext(new Node(it, curr)); countOfElements++; }

This method moves a pair of pointers, curr and prev, a number of times (idx) until they point to the location where you want to insert the new node. In your code, the code you need to come up for the add() method in the ListNodePlus class, you need to do something VERY similar. You need to move curr and prev until you find the place where you will insert the new node. But, instead of moving it a number of times, you move them until you find the place based on the order of the data.