This repo contains an IntelliJ project for the 2021 final exam.
You have 3 hours and 30 mins to complete the exam.
This exam is open-book, meaning you may use books, notes, and other such pre-existing information as you complete the exam.
You must 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 before the exam and must remain off for the duration of the exam. The penalties for cheating in an exam at ANU are severe.
Important notes:
- There are six (6) questions, each worth different marks.
- The total marks for the exam are 85 (10 + 5 + 25 + 20 + 5 + 20)
- The exam will be entirely auto-graded, so it is important that your code passes the tests and that you commit and push your work.
- The CI for the multiple-choice question will not tell you whether your answer is correct; it will only tell you if your answer is formatted correctly.
- We have provided two practice questions, P1 and P2, to help you prepare your environment for the exam. You do not need to complete them. They are worth zero marks.
Using the incomplete template for Q1FindAllStarting.java,
complete the unimplemented method findAllStarting().
Use the tests provided to test your solution, and then commit and push your changes to GitLab.
Using the incomplete template for Q1Alternating.java, complete the unimplemented method alternating().
Use the tests provided to test your solution, and then commit and push your changes to GitLab.
Using the incomplete template for Q2AsciiSum.java,
complete the unimplemented method asciiSum().
Use the tests provided to test your solution, and then commit and push your changes to GitLab.
Using the incomplete template for Q3Recipes.java, complete all unimplemented methods.
You must complete your solution as a single file, Q3Recipes.java.
You are encouraged to create additional classes as required to solve the problem;
any additional classes must be implemented as nested classes within the
Q3Recipes class.
Use the tests provided to test your solution, and then commit and push your changes to GitLab.
Using the incomplete template for Q3GetMaxRecipesInCategoryTest.java,
write one or more unit tests for the getMaxRecipesInCategory() method. You must complete
your solution as a single file, Q3GetMaxRecipesInCategoryTest.java. When writing the
tests, you may assume that the provided methods in the Q3Recipes class are
correctly implemented. The specification of the getMaxRecipesInCategory() method
is provided in the Javadoc comment immediately above the method.
This question is auto-graded; your tests will be run against multiple
implementations of the getMaxRecipesInCategory() method,
one of which is correct and some incorrect. Your test must be able to pass
the correct implementation. If you cannot pass the correct implementation
you will get zero (regardless of how many incorrect implementations you fail.
If you pass the correct implementation, you will get one mark, and then one
additional mark for each incorrect implementation that you fail.
Once you have completed your tests, commit and push your changes to GitLab.
Using the incomplete template for Q4Replicator.java, complete each of the unimplemented methods.
Your solution must implement the data structure from first principles (as was done in lectures), avoiding use of Java's collection classes such as java.util.List.
Solutions that ignore this requirement will be penalized accordingly.
Use the tests provided to test your solution, and then commit and push your changes to GitLab.
Using the incomplete template for Q5Monarch.java, complete the unimplemented methods hash() and equals().
You must implement hash() without using Java's built-in hashCode() method.
Use the tests provided to test your solution, and then commit and push your changes to GitLab.
For each of the following multiple-choice questions, identify the choice that provides the best answer. Record your choices in the file q-6.csv, one line per question.
For example, to answer "a" to question Q6.1, "d" to question Q6.2, "a" to
question Q6.4, and leave question Q6.3 unanswered, you would record the following
in q-6.csv:
1,a
2,d
4,a
Please note that you can only provide one answer to any multiple choice question. Please chose the answer that you think is the best answer. If you are unsure, leave it out, as in the example above where question 3 is left out.
Each question that is correctly answered gains you 5 marks, each question answered incorrectly loses you 1 mark, a question left unanswered neither loses nor gains marks. The final mark for the question is calculated by bounding the sum of marks between 0 and 20. For example, if you answered all questions correctly in the exam you would gain 20. If you answer 1 correctly and 2 incorrectly you would gain 3/20.
The exam CI will check whether your answer is correctly formatted. Note that
the CI won't tell you whether your answer is correct. After you finish your
questions you should commit your q-6.csv file and push it to the
server. You should check the CI for any error messages relating to Q6 and
fix them if they exist.
The code below is for a program in which workers each complete work items from a shared work queue. There are two workers, each of which must complete ten work items, so the program should print the numbers [0..19] (not necessarily in that order). However, the code has a race condition, which means that it does not always print the correct output.
public class Workers implements Runnable {
static class State {
static State instance; // a
int workItem; // b
public static State load() {
if (instance == null) {
instance = new State();
}
return instance;
}
public synchronized int getWorkItem() {
return workItem++;
}
}
public void run() {
for (int i = 0; i < 10; i++) { // c
State s = State.load(); // d
int w = s.getWorkItem(); // e
System.out.println(w);
}
}
public static void main(String[] args) {
Workers g = new Workers(); // f
(new Thread(g)).start();
(new Thread(g)).start();
}
}
In the code above, a race condition on which field or variable may cause incorrect output?
a) State s
b) State.instance
c) int i
d) State.workItem
e) int w
f) Workers g
Consider the following JavaFX application methods:
static void squares(Pane parent, int level) {
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
if (level > 1) {
var p = new TilePane();
p.setPrefColumns(3);
squares(p, level-1);
parent.getChildren().add(p);
} else {
var r = new Rectangle(15, 15);
r.setFill((i * 3 + j) % 2 == 1 ? Color.RED : Color.BLACK);
parent.getChildren().add(r);
}
}
}
}
public void start(Stage stage) throws Exception {
var root = new Group();
var scene = new Scene(root, 405, 405);
var p = new TilePane();
p.setPrefColumns(3);
squares(p, 3);
root.getChildren().add(p);
stage.setScene(scene);
stage.show();
}
How many nodes are in the scene graph of the application?
a) 730
b) 729
c) 9
d) 405
e) 821
f) 27
Consider the method z() below.
static <T extends Comparable<T>> void z(List<T> l) {
for (int i = 0; i < l.size(); i++) {
T v = l.get(i);
int j = i;
int k;
for (k = 1; k < l.size(); k = k * 2) {
l.set(j, l.get(k));
j = k;
}
l.set(j, v);
}
}
Which of the following statements is correct?
a) The time complexity of z() with l of size n is O(2 n).
b) The time complexity of z() with l of size n is O(n).
c) The time complexity of z() with l of size n is O(n log n).
d) The time complexity of z() with l of size n is O(n^2).
This question relates to sentences (statements) in a language defined by a simple EBNF grammar. For reference, some symbols of EBNF are as follows:
= defines a production rule
, concatenation
| alternation / choice
[...] optional - zero or one
{...} optional - zero or more
(...) grouping
- exception
; terminates a production rule.
Given the following EBNF grammar:
vowel = 'a' | 'e' | 'i' | 'o' | 'u' ;
consonant = 'h' | 'k' | 'l' | 'm' | 'n' | 'p' | 'w' | 'ʻ' ;
syllable = consonant , vowel, [ vowel - 'a' ];
word = ( vowel | syllable ), { syllable } ;
Identify which of the following strings cannot be produced by the grammar.
lauleʻa
b)
hoʻoponopono
c)
kokua
d)
maikaʻi
e)
puʻuwai
This is the end of the exam. Instructions for the practice questions follow.
These are instructions for what to do before the exam.
You should complete the two practice questions below and ensure that they work in your environment. Please check that:
- the provided test for P1 runs correctly in IntelliJ;
- you can successfully pass the test for P1;
- you can fill in the answers for P2;
- you can commit and push your work; and
- the CI says that you have passed P1 and that P2 has been checked.
Note that the CI will not tell you whether the multiple-choice question P2 is correct or incorrect, it will only tell you whether it was correctly formatted.
Remember, the questions below are practice questions which you should attempt before the exam. The practice questions exist only to help you check that your environment is working correctly. The practice questions are not worth any marks.
The first is an example of a programming question.
Using the incomplete template for P1HelloWorld.java, complete the unimplemented main method.
Use the tests provided to test your solution, and then commit and push your changes to GitLab.
For each of the following multiple-choice questions, identify the choice that provides the best answer. Then, record your choice in the file p-2.csv, one line per question.
For example, to answer "a" to practice question P2.1, "d" to P2.2, "a" to P2.4, and leave P2.3 blank, you would record the following
in p-2.csv:
1,a
2,d
4,a
These practice questions are worth zero marks. In the actual exam, there will be four multiple-choice questions. Each correct answer gains you 5 marks; each incorrect answer loses you 1 mark; a question left unanswered neither loses nor gains marks. The final mark for the question in the exam is calculated by bounding the sum of marks between 0 and 20. For example, if you answered all questions correctly in the exam, you would gain 20. If you answer 1 correctly and 2 incorrectly, you would gain 3/20.
Once you have answered the questions, you should commit your p-2.csv file and push it.
You should check the exam CI to see whether it passed the formatting check.
If it did not, you should read the error messages and fix up any formatting problems with your answer.
Note that the CI won't tell you whether your answers are correct, only whether they are correctly formatted.
Which of the following colours best represents the colour of the sky?
a) blue
b) green
c) pink
d) purple
e) yellow
Which of the following numbers best represents the result of the
addition 2 + 2?
a) 3
b) 2
c) 4
d) 5
e) 1
Which of the following animals is most closely associated with Australia?
a) tiger
b) elephant
c) kangaroo
d) lion
e) bear
Which of the following brands is best known as a car manufacturer?
a) Microsoft
b) Qantas
c) Toyota
d) Coca Cola
e) Facebook