Description
You will implement seven classes which form the basis for a simple game simulation. A World will contain several Clans.
A Clan will contain a number of Citizens. There will be two types of Citizens: Civilians and Fighters. There will be two
types of Fighters: Archers and Barbarians. The simulation starts with several clans in the world, each containing random
citizens. Repeatedly, one clan will attack another one. The civilians are not affected (unlike in real life), but the fighters
damage or kill each other. When a clan loses all its fighters, it is removed from the world. The attacks continue until only
one clan is left.
In this assignment you will practice how to implement concepts such as defining hierarchies of classes, abstract classes,
and polymorphism. Please keep all of your methods short and simple. Make sure to call methods already created when
appropriate, instead of duplicating code for no reason. Unless specified otherwise, all instance variables must be
private, and all methods should be public. Also, unless specified otherwise, there should be no println statements
in your classes. Objects usually do not print anything; they only return String values from methods. Make sure the
outputs of the methods, including toString methods, in your classes, are exactly the same as the outputs explained in
the instructions.
Instructions
A java file, TestA3.java, will be given to you which contains a main program which will control the overall simulation.
You must write all of the following classes for this game.
1: The Citizen class:
Create an abstract Citizen class. Since it will not be possible to create an object of this class, its methods will be very
simple. There are no instance variables. This class exists only to allow polymorphism to occur later.
• Implement a String toString() method which returns “Citizen”.
• Implement randomCitizen() method, that is a static method which will return a random Citizen. It should return
a Civilian, Archer, or Barbarian, at random. (You will need to implement those classes first.)
2-The Civilian class:
Create a Civilian class as a subclass of the Citizen class.
ASSIGNMENT 3: Advanced topics in OOP
COMP 1020 Fall 2020
Page 2 of 6
• Implement a String toString() method which returns “Civilian”.
• This class must have no instance variables, and no other methods.
3-The Fighter class:
Create an abstract Fighter class as a subclass of the Citizen class.
• Fighters have two private int instance variables: the “currentHealth”, and the “currentAttack”. When fighters
attack each other, each one’s attack power is used to decrease the other one’s health. When a fighter’s health
reaches 0, it dies.
• Create a custom constructor with two parameters which initializes both the health and the attack power. The
first input parameter of your constructor should be currentHealth and the second one should be currentAttack.
• Implement a String toString() method which returns “Fighter” followed by the values of health and attack
power.
o Fighter: health=100 attack=15
o Fighter: health=116 attack=10
• Provide accessor (get) methods only if needed by other classes.
• Do not provide any mutator (set) methods. The instance variables must be strictly private! These values are
changed only by the following methods.
• Write a method decreaseHp(int) which will reduce the health of this fighter by the given amount. Health should
not go below 0.
• Write a method boolean isDead() which will detect when the fighter is dead (health is zero).
• Write a method void gainPower() which does nothing. But subclasses of this class will use this method, and so
the superclass must also have one to allow polymorphism.
• Write a method void gainPower(int) which increases the attack power by the given amount. Survivors of a fight
will gain attack power, and this can be useful in the subclasses to override the gainPower() method.
• Note that health only goes down, never up, and attack power only goes up, never down. “What doesn’t kill you
makes you stronger.”
4-The Archer class:
Create an Archer class as a subclass of the Fighter class.
• Archers always start with 100 health and 15 attack power. Provide a constructor with no parameters which
does this.
• Implement a String toString() method which returns the String produced by the Fighter superclass, with
“(Archer)” added to the end.
o Fighter: health=100 attack=15 (Archer)
• Write a method void gainPower() which adds 10 to the archer’s attack power.
5-The Barbarian class:
Create a Barbarian class as a subclass of the Fighter class.
• Barbarians always start with 200 health and 20 attack power. Provide a constructor with no parameters which
does this.
• Implement a String toString() method which returns the String produced by the Fighter superclass, with
“(Barbarian)” added to the end.
o Fighter: health=145 attack=110 (Barbarian)
• Write a method void gainPower() which adds 15 to the barbarian’s attack power.
6-The Clan class:
Create a Clan class.
• A clan must have a name, and a list of Citizens.
ASSIGNMENT 3: Advanced topics in OOP
COMP 1020 Fall 2020
Page 3 of 6
• Provide a constructor with the header public Clan(String clanName, int clanSize) which will create a clan with
the given name, and the given number of citizens. The number of citizens will never change later, although some
of them (the fighters) may become dead. The constructor should create and store the correct number of random
citizens, using the randomCitizen method of the Citizen class.
• Since a clan will be deleted from the game when it has no fighters left, it is important that the clan has at least
one to start with. Make sure the first citizen is an Archer or Barbarian.
• Provide a getName() accessor method.
• Write a private int totalAttackPower() method which will find the total attack power of all Fighters in this clan
who are not dead (sum of all attack power of all Fighters).
• Write a private int numFightersAlive() method which will count the number of Fighters in this clan who are not
dead.
• Write a method with the header public void attack(Clan others) which will cause two clans to fight each other
(this clan, and the others). When clan A attacks clan B, the maximum possible damage to members of clan B is
the total attack power of clan A divided by the number of living fighters in clan B. The health of each living fighter
in clan B should be reduced by a random value between 0 and this maximum value. This should be done in both
directions as if both clans are attacking each other at the same time (this clan attacks the others, but the others
attack this clan, too.)
• Write a boolean isDead() method which will return true if there are no living fighters in this clan.
• Write a void gainPower() method which will increase the attack power of every living fighter in this clan. This
will be called (in the World class, below) to increase the power of the survivors of a fight. Don’t increase the
attack power of dead fighters!
• Provide the usual String toString() method, which will return a multi-line String showing the information on the
whole clan:
o The first line should give the clan’s name.
o The second line should give the clan’s total attack power.
o The remaining lines should list the citizens, one per line, using the Strings provided by their toString
methods. Do not list dead fighters, only living ones.
o Follow the example here:
Clan Raiders:
Total attack power: 440
Fighter: health=87 attack=110 (Barbarian)
Fighter: health=145 attack=110 (Barbarian)
Civilian
Fighter: health=116 attack=110 (Barbarian)
Fighter: health=134 attack=110 (Barbarian)
7-The World class:
Create a World class. The world will contain a list of all of the clans, and provide a few methods that will complete the
functionality of the game.
• A World must have instance variable(s) that store a list of up to 10 Clans. The number of clans will change
during the game.
• Provide a constructor (no parameters) that creates a world containing no clans.
• Provide a void addClan(Clan c) method to add a new clan to the world. You do not need to check to see if the
maximum number of clans has been exceeded.
• Provide an int getNumClans() method which will return the current number of clans in the world.
• The most important method is void attack(int clan1, int clan2) which will cause the two clans to attack each
other. (The clans are identified by index number, not by name.) It should print a message indicating that this is
happening, including the names of the two clans. Surviving fighters in each clan should gain power. If either (or
both) clans no longer have any living fighters, they should be deleted from the world. A message should also
be printed when a clan is deleted. You may want to write additional private methods to support this method.
ASSIGNMENT 3: Advanced topics in OOP
COMP 1020 Fall 2020
Page 4 of 6
• Provide a String toString() method that will return a multi-line String listing the entire world, and all the clans
in it. It should give the number of clans in the world, and then list each clan. Add some sort of dividing line to
separate the clans and make them more visible. See the sample output that follows.
There are 3 clans in the world.
—–
Clan Settlers:
Total attack power: 65
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=100 attack=15 (Archer)
Civilian
Civilian
Fighter: health=100 attack=15 (Archer)
Fighter: health=100 attack=15 (Archer)
—–
Clan Raiders:
Total attack power: 80
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=200 attack=20 (Barbarian)
Civilian
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=200 attack=20 (Barbarian)
—–
Clan Hordes:
Total attack power: 75
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=200 attack=20 (Barbarian)
Civilian
Civilian
Fighter: health=200 attack=20 (Barbarian)
Civilian
Fighter: health=100 attack=15 (Archer)
8-The TestA3 class:
This class is provided for you to test Assignment 3. It creates a world containing 3 clans, and then causes pairs of these
clans to attack each other until only 1 (or perhaps 0) clans remain in the world.
See the Sample output on the last page. Your output should be similar to this, but it does not have to match it exactly.
Every time the program runs, the output will be different, because the game is random. Choose a test run that is not too
large, but shows that your program works as it should. Put the output from that test run into a text file, and hand it in with
your assignment. Name the file YourNameA3output.txt.
Hand in
Submit only the .java files for your seven classes (Citizen, Civilian, Fighter, Archer, Barbarian, Clan and World). Do not
submit .class or .java~ files! You do not need to submit the TestA3.java java files that were given to you. If your
submitted code fails to compile and run, you will lose all of the marks for the test runs. The marker will not try to run
anything else, and will not edit your files in any way. Make sure none of your files specify a package at the top,
otherwise your code will not compile on the marker’s computer!
ASSIGNMENT
3: Advanced topics in OOP
COMP 1020 Fall 2020
Page
5 of
6
There are 3 clans in the world.
—–
Clan Settlers:
Total attack power: 65
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=100 attack=15 (Archer)
Civilian
Civilian
Fighter: health=100 attack=15 (Archer)
Fighter: health=100 attack=15 (Archer)
—–
Clan Raiders:
Total attack power: 80
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=200 attack=20 (Barbarian)
Civilian
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=200 attack=20 (Barbarian)
—–
Clan Hordes:
Total attack power: 75
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=200 attack=20 (Barbarian)
Civilian
Civilian
Fighter: health=200 attack=20 (Barbarian)
Civilian
Fighter: health=100 attack=15 (Archer)
Clan Settlers attacks Raiders!
There are 3 clans in the world.
—–
Clan Settlers:
Total attack power: 110
Fighter: health=182 attack=35 (Barbarian)
Fighter: health=88 attack=25 (Archer)
Civilian
Civilian
Fighter: health=82 attack=25 (Archer)
Fighter: health=80 attack=25 (Archer)
—–
Clan Raiders:
Total attack power: 140
Fighter: health=195 attack=35 (Barbarian)
Fighter: health=197 attack=35 (Barbarian)
Civilian
Fighter: health=190 attack=35 (Barbarian)
Fighter: health=193 attack=35 (Barbarian)
—–
Clan Hordes:
Total attack power: 75
Fighter: health=200 attack=20 (Barbarian)
Fighter: health=200 attack=20 (Barbarian)
Civilian
Civilian
Fighter: health=200 attack=20 (Barbarian)
Civilian
Fighter: health=100 attack=15 (Archer)
Clan Hordes attacks Raiders!
ASSIGNMENT 3: Advanced topics in OOP
COMP 1020 Fall 2020
Page 6 of 6
There are 3 clans in the world.
—–
…More attacks happen…
Clan Raiders attacks Settlers!
Clan Settlers is wiped out!!
There are 2 clans in the world.
—–
Clan Raiders:
Total attack power: 440
Fighter: health=87 attack=110 (Barbarian)
Fighter: health=145 attack=110 (Barbarian)
Civilian
Fighter: health=116 attack=110 (Barbarian)
Fighter: health=134 attack=110 (Barbarian)
—–
Clan Hordes:
Total attack power: 285
Fighter: health=76 attack=95 (Barbarian)
Fighter: health=32 attack=95 (Barbarian)
Civilian
Civilian
Fighter: health=34 attack=95 (Barbarian)
Civilian
…More attacks happen…
Clan Raiders attacks Hordes!
Clan Hordes is wiped out!!
There are 1 clans in the world.
—–
Clan Raiders:
Total attack power: 465
Fighter: health=41 attack=155 (Barbarian)
Civilian
Fighter: health=31 attack=155 (Barbarian)
Fighter: health=58 attack=155 (Barbarian)
Game Over.