Lab 8

Logistics

Due: on Thursday, October 20th anywhere on earth (6am Friday). (Penalties from the syllabus apply if you turn it in any later.)
Submission instructions: you have two options. The first option is to demonstrate the execution of your lab to your TA during your assigned lab section on Thursday. The second option is to submit your Java file(s) on D2L.

Learning outcomes

Understand doubly linked lists

Assignment

Download DoublyLinkedList.java, the book’s doubly linked list implementation. Compare it to the Java LinkedList. You’ll notice that the book’s implementation is missing quite a few methods! In this lab, you’ll write some of those.

Modifier and Type	Method	Description
`void`	`add(int index, E element)`	Inserts the specified element at the specified position in this list.
`void`	`add(E e)`	Appends the specified element to the end of this list.
`void`	`clear()`	Removes all of the elements from this list.
`E`	`get(int index)`	Returns the element at the specified position in this list
`E`	`set(int index, E element)`	Replaces the element at the specified position in this list with the specified element.

Hints

Take a good look at the private method addBetween() and make sure you understand it. Even though it is private and can’t be called outside of DoublyLinkedList, it is very powerful can be reused by other methods within DoublyLinkedList. We want to write programs that are D.R.Y. (do not repeat code), so make sure you call addBetween() when you need to.
You can test that your implementation is working correctly by importing java.util.LinkdedList, creating one, and make sure that your DoublyLinkedList works the same when you call your methods.

Sample output

You should demo each method. Here’s an example. Your implementation is generic, so you could also try your methods on other types besides integers.

Add Integers: 5 9 1 8
(5, 9, 1, 8)
Add Integer 7 at index 2:
(5, 9, 7, 1, 8)
Add Integer 7 at index 8:
Index 8 out of range.
(5, 9, 7, 1, 8)
Clear the list:
()
Add 10 11 12 13, get index 3:
value is 13
Get index 4:
Index 4 out of range.
value is null
Set index 2 to 22:
(10, 11, 22, 13)
Set index 7 to 77:
Index 7 out of range.
(10, 11, 22, 13)

Grading - 10 points

8 points: implement and demo each method (2 points each)
2 points: DRY code

Grading turnaround

This lab will be graded with scores in Brightspace before Tuesday, October 25th.