From Assignment 2 you only need one of these methods to be correct. Adjust method load() accordingly (read comments in Tester).

Method addLast is easier and requires only 4 lines.

Contact the instructor immediately if you could not get either of these to work.

Removes the first element in the list.

JUnit: _?_ cases

Removes the last element in the list.

JUnit: _?_ cases

Removes the element at the given index.

JUnit: 10 cases

Removes all occurrences of the given item in the list; do not use remove(E item) (why?), manipulate the pointers explicitly.

JUnit: 10+ cases. Here it would be good to try different multi-lists list (e.g. list with sections of adjacent identical elements in the right places, list with distinct elements).

Implement the method of the DListIterator class. (see Iterator). Note that before each call to remove() there must have been a call to next(). In other words, the iterator does not allow:

• successive calls of remove()
• a call of remove() as soon as the Iterator is constructed

In each case IllegalStateException is thrown. You will need to add a boolean data member to the iterator class, see Stack.java, IteratorTest.java

JUnit: No JUnit test cases are needed. This is a method of the inner iterator class and will be tested implicitly in JUnit by testing the method removeAllIter(...).

Same as removeAll but uses an iterator over this list to visit the nodes and remove them.

This method must use while loop, since .remove() of iterators cannot be called inside enhanced for loop.

The should be no Node code anywhere in this method.

JUnit: same as removeAll

Add this method in the Tester class. For each type of list (empty, single, multi), it tests that list's iterator for all possible failing conditions of the methods next() and remove(), i.e. the conditions under which these methods throw exceptions.

The goal is to have each line in the Iterator class marked green.

JUnit: To test you could write:

list = load( m,y,n,u,m,b,e,r,s);
Iterator<???> iter = list.iterator();
assertTrue(iter.next(), ...) or iter.remove() [sometimes in try/catch]
assert toStingNext/Prev for the list

Determines if this list is equal to the given list (i.e. have the same contents).

Implement this using two iterators (one for this list and one for the given list) and a while loop. The should be no Node code anywhere in this method.

Here is an example of the typical steps in implementing the method equals: Cat.java. Note that a typecast is required to convert from Object to the specific class.

JUnit: Compare the lists with themselves, with each other, and with things that are not lists. Note, that these tests are not likely to be sufficient.