Assignment 1: Designing complex data
Goals: Practice designing the representation of complex data.
1.1 Instructions
This homework should be done with your partners (that you will work with starting from Lab 1). You may begin working on the assignment on your own before lab, and then combine work with your partner after lab.
the names of classes,
the names and types of the fields within classes,
the names, types and order of the arguments to the constructor, or
filenames,
You will submit this assignment by the deadlines using the course handin server. Follow A Complete Guide to the Handin Server for information on how to use the handin server. You may submit as many times as you wish. Be aware of the fact that close to the deadline the server may slow down to handle many submissions, so try to finish early. There will be a separate submission for each problem - it makes it easier to grade each problem, and to provide you with the feedback for each problem you work on.
The four submissions will be organized as follows:
Homework 1 Problem 1: The University.java file
Homework 1 Problem 2: The StudyGroup.java file
Homework 1 Problem 3: The ExamplesGame.java file
Homework 1 Problem 4: The BouncingBalls.java file
Due Date: Tuesday, January 16th, 9:00 pm
Practice Problems
Work out these problems from How to Design Classes on your own. Save them in an electronic portfolio, so you can show them to your instructor, review them before the exam, use them as a reference when working on the homework assignments.
Problem 2.4 on page 17
Problem 3.1 on page 25
Problem 4.4 on page 34
Problem 5.3 on page 43
Problem 10.6 on page 102
Problem 11.2 on page 113
Problem 14.7 on page 140
Problem 1
Everywhere in this assignment that you see italic, fixed-width text, it is intended to be the name of a field, identifier, class name or interface name you must define...but you likely must modify that name a bit to conform to our Java naming conventions: hyphenated-names are written in camelCase, and interface names begin with an uppercase I.
Everywhere that you see fixed-width text, it is exactly the name you must use.
name: the name of the university, as a String
city: where the university is located, as a String
studentSize: the number of students they have this year, as an int
mostPopularMajor: the name of the most popular major, as a String
averageGPA: the average GPA of the current student population, as a double
hasCoop: a boolean representing whether or not the university offers a co-op program
Make at least three examples of instances of this class, in the class ExamplesUniversity. Two of the examples should be objects named neu and yale and should represent the following two universities:
Yale, a university in New Haven with 14,567 students, economics as a most-popular major, an average GPA of 4.14, and no co-op program
Northeastern, a university in Boston with 19,940 students, engineering as a most-popular major, an average GPA of 4.04, and (obviously!) a co-op program
Problem 2
Here is a data definition in DrRacket:
;; A StudyGroup is one of: ;; -- Person ;; -- StudyBuddy ;; A Person is a (make-person String) (define-struct person [name]) ;; A StudyBuddy is a (make-study-buddy StudyGroup String) (define-struct study-buddy [connection name])
Draw the class diagram that represents this data definition. You may draw this as ASCII-art and include it in your submission, if you wish. Or you can just draw it on paper and not submit it. Regardless, we think it will help you in visualizing how the data is organized.
Convert this data definition into Java. Make sure you use the same names for data types and for the fields, as are used in the DrRacket data definitions, converted into Java style standards. Make sure that the constructor arguments are given in the same order as shown.
Include in your examples the following study groups
– "Margaryta" has a study group of "Regan".
– "Ted" has a study group of "Liz", "Jenny", and "Cornelius".
The order of friends in a person’s study group doesn’t matter. But study buddies are definitely distinct from the primary person in the study group, and should not be conflated.
Make sure the two sample study groups given above are named labs and largeGroup.
Name your file StudyGroup.java. Name the class that holds the examples of your data ExamplesStudyGroup.
Problem 3
We’ve been asked to help build a new deck-building game, Drydock. To start, we’re designing representations for the resources a player can have and the actions they can take during their turn. A player can have three kinds of resources: Captain, Crewmember, and Ship.
A Captain has a name and a number of successful battles (as an integer).
A Crewmember has a name, a description of their role on the ship, and an integer wealth value representing how many gold coins they have to their name.
A Ship has some description of its purpose and a flag hostile denoting whether it will plunder other ships unprompted.
As the game is under construction, the player can only perform two kinds of actions right now: they can Purchase a resource from the common pool, or they can Barter to swap a resource in their hand with one from the discard pile.
To purchase an item, the player must pay an associated cost, which must be a positive integer. They then receive the purchased resource item.
Every swap action has a sold resource and an acquired resource. The value of the acquired resource must be no more than 2 greater than the value of the sold resource. A captain is worth its battles, a crewmember is worth their wealth, and a ship is either worth 50 or 100, based on its hostility (hostile ships obtain more loot and are therefore more expensive).
- Define six examples of resources, including:
jackSparrow: name "Jack Sparrow", battles 89
hectorBarbossa: name "Hector Barbossa", description "first mate", wealth 52
flyingDutchman: purpose "sail the oceans forever", hostile
The others can be whatever you wish. Define four types of actions, two of each kind.
Name your action examples purchase1, barter2, etc., and your examples class ExamplesGame. You haven’t learned yet how to check the described consistency requirements in Java, but make sure your examples follow them.
Problem 4
Complete the Bouncing Balls portion of the lab and hand it in. Hint: think carefully about exactly what causes a ball to bounce...and test your code well to figure out any subtle cases. The methods which were added to Ball earlier in the lab should also exist in BouncingBall.