COMP1110/1140/6710 Final Exam

This repository contains the IntelliJ project for the 2022 S2 final exam.

You have 3 hours and 15 minutes to complete the exam.

The question is marked out of 100, and accounts for 40% of your final course mark. Marks for each question are specified below.

This exam is open book. This means that you may use books, notes, and any other such pre-existing information as you complete the exam.

You must, however, not communicate with any person other than the examiners at any time during the exam. Chat, text, email and all other such forms of communications must be turned off prior to the exam and must remain off for the entire duration of the exam. You may only use the class piazza forum. Do not post to piazza visible to all during the exam. The penalties for cheating in an exam at ANU are severe.

Advice

• Read all questions and instructions carefully.

• Questions are not ordered by difficulty. Some questions are meant to be significantly harder than others (Q3, for example, is one of the hard ones). Take the time to read through all questions at the start of the exam, and solve the ones you think will be easy first.

• Programming questions are marked on functionality, as determined by testing. Code style does not matter.

• We will test your code with additional test cases other than those that are provided here, so it is important that you read and understand the specification of the method/methods that you are asked to implement, and implement that specification correctly. The tests that are provided are meant to help you do that, but the tests are not the specification.

• A partially correct implementation (i.e., one that passes some tests but not all) will usually receive some marks. (There are exceptions, for example in cases where a “dummy” implementation like always returning false happens to pass a certain test; then there will be no marks for passing that particular test only.). However, marks are not necessarily proportional to the number of tests passed.

• Some questions have an explicit breakdown of marks for parts or levels of functionality. (For example, Q4 has some marks for implementing methods correctly, and some additional marks for implementing them correctly and in amortised constant time.) Again, think about solving the easy part/level first, and attempt the harder one if you have time.

• Commit and push your work regularly as you complete it. Access to the exam gitlab will close at the end of your exam time, and after that you will not be able to push anything more. We will only mark what is in your exam repository on the gitlab server after the exam.

  Close to the end of the exam (last 10-15 minutes), the exam server is likely to be very busy, and pushing can take much longer than normal. Be prepared for that - don't leave pushing to the last minute!

• Note that the exam server does not have CI (server-side testing) enabled. To test your solutions, you will have to run the provided tests in your IDE. (This also means when you push, you don't have to wait for CI to finish.)

  Do not modify the intelliJ project settings, since that may cause some of the tests to break.

Q1 [15 Marks] Programming

Using the template Q1AverageInRange.java, complete the unimplemented method averageInRange.

Q2 [15 Marks] Programming

Using the template Q2ThreeOdd.java, complete the unimplemented method threeOdd.

Q3 [15 Marks] Programming (search problem, hard)

Using the template Q3Schedule.java, complete the unimplemented method maximalSchedule.

Q4 [15 + 5 Marks] Implementation and computational complexity

Using the template Q4Sources.java, complete all unimplemented methods. You must also add fields to the class, as necessary to implement the specified method functionality.

You must complete your solution within the single file, Q4Sources.java. You can, and indeed are incouraged to, create additional classes if that helps you solve the problem, but any additional classes must be implemented as nested classes within the Q4Sources class.

Note that this question has two levels of diffculty:

For level 1 (15 marks), you are only required to implement the functionality specified for each method. Use the tests provided (Q4SourcesTest) to test your implementation for correctness.

For level 2 (5 additional marks), you must implement the methods so that they are not only functionally correct, but also run in amortised constant time. (In other words, the difference between level 1 and 2 is not what you implement, but how.) To help you test the scaling behaviour of your implementation, a scaling test is implemented in the main method of the Q4Sources class. If your solution meets the amortised constant time requirement, you should find that the test runtime is approximately equal for increasing network sizes. If you see a consistent trend for the time to increase as the network size increases, then your implementation (of at least some method) is probably not constant time.

Remember to commit and push your work!

Q5 [15 Marks] Testing

Using the template Q5IsIncreasingTest.java, write at most 5 unit tests for the isIncreasing method in the IsIncreasing.java class. The method is not implemented, but the javadoc comment describes what a correct implementation of the method is meant to do.

• You can write up to 5 tests (assertions) in the one test method, or split them over several test methods, as you prefer. However, all your test methods must have the @Test annotation.

• Your tests should cover all edge cases.

• A correct implementation should pass all your tests. (If you want to, you can write a correct implementation of the isIncreasing method to test that your tests meet this requirement.)

• Note that the IsIncreasing class is generic: to test the method, you must instantiate the class with a type of your choice; you can use different types for different tests.

Remember to commit and push your work.

Q6 [15 Marks] Hashing and equality

Using the template Q6StringPattern.java, implement equals and hashCode in both subclasses StringConstant and StringOperator.

Use the tests provided in Q6StringPatternTest.java to test your implementation.

Marks for this question are divided between implementing the equals and hashCode methods correctly (12 marks, tests testEquals, testHashEq and testHash2) and implementing a good hash function (up to 3 additional marks, tests testHash6 and testHash16).

Q7 [5 Marks] JavaFX Programming

Using the template Q7TrafficLight.java, complete the event handlers to make the application have the following behaviour:

• When the "Go" button is pressed, set the colour of the lower circle to GREEN and the colour of the upper circle to GRAY.
• When the "Stop" button is pressed, set the colour of the upper circle to RED and the colour of the lower circle to GRAY.
• When the "Reset" button is pressed, set the colour of both circles to GRAY.

A method setColor and predefined red, green and gray colours are provided to help you. You can make other changes to the class (such as add fields or methods) if you think it is helpful, but you must not modify the UI components (that is, not change the nodes in the scene or their layout).

Note that there are no unit tests for this question; you will have to test it yourself.