Lecture 11: Review for Exam

Announcements

H4: was due at noon today – on-line handin

look at the posted solution

exam: Thursday, 7:15pm, 1240 CS

one page of notes

bring a pencil

P2: due tonight at midnight

demo contained errors – have been corrected; let me know

inserting a duplicate task didn't throw an exception

error message for bad file didn't name the file

list can contain null

§ your contains(ob) method should handle that case

§ don't have to worry about that on the exam

if you add a duplicate task, it should throw an exception

Exam topics:

Lists

· the List ADT

· ArrayList and LinkedList implementations

· manipulations of linked data structures

· downcasting when retrieving items of a specific type

· iterators

Complexity, big-O notation

worst case running times for

· ArrayList methods

· LinkedList methods (singly-linked list, lastNode field)

· doubly linked lists

· code we give you

Exceptions

· how to throw, how to catch

throw new ex-type(); //note "new" and "()"

try{ … } catch(IOException ex) {…}

· how to define a new exception

public class myException extends RuntimeException {

} // often leave the exception class empty

· checked vs unchecked

Stacks & queues

· complexity of operations

· how to write code to use them

· not: how to implement Queue using an array or ArrayList

iterators

import java.util.* // defines the Iterator type

public Iterator iterator() { // in the ArrayList class

return new ListIterator(this);}

class ListIterator implements Iterator{

… // define fields here

public Boolean hasNext(){…}

public Object next() {…}

public void remove() {…}

}

Iterator it = L.iterator();

while (it.hasNext()) {

ob = it.next();

…

}

or

for (Iterator it = L.iterator(); it.hasNext(); ) {

Object ob = it.next();

…

}

Previous exams

Fall 03

o ignore Part II Q3: array implementation of Queue

o ignore circular list in Part II Q1

o part I Q6: not well-worded

Fall '99

o ignore Part I Q9 & Q10: circular array implementations

Thursday's exam

· similar range of questions

· similar difficulty

· some questions are subtle, read all possible answers

· don't rush through

Lecture 12: exam #1