On this page:
1.1 Instructions
Practice Problems
Problem 1: Our Canine Friends
What to submit
Problem 2: Icecream
What to submit
Problem 3: Traveling
What to submit

Assignment 1: Designing complex data

Goals: Practice designing the representation of complex data.

1.1 Instructions

Be very, very careful with naming! The solution files expect your submissions to be named a certain way, so that they can define their own Examples class with which to test your code. Therefore, whenever the assignment specifies:
  • 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,

...be sure that your submission uses exactly those names. Additionally, make sure you follow the course style guidelines. For now the most important ones are: using spaces instead of tabs, indenting by 2 characters, following the naming conventions (data type names start with a capital letter, interfaces begin with an uppercase I, names of fields and methods start with a lower case letter), and having spaces before curly braces.

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.

Due Date: Thursday, 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.

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.

Problem 1: Our Canine Friends

We are designing the data collection for the American Kennel Club. For each dog we need to collect the following information:

Design the class Dog that represents the information about each dog for the census.

Make at least three examples of instances of this class, in the class ExamplesDog. Two of the examples should be objects named huffle and pearl and should represent the following two dogs:

What to submit

You should submit your data definitions and examples in a file named Dog.java

Problem 2: Icecream

Here is a data definition in DrRacket:

;; An IceCream is one of:
;; -- EmptyServing
;; -- Scooped
;;An EmptyServing is a (make-empty-serving Boolean)
(define-struct empty-serving (cone))
;;A Scooped is a (make-scooped IceCream String)
(define-struct scooped (more flavor))

Make sure the two sample orders given above are named order1 and order2. Note: the descriptions above are listed in the order that you would order this in real life. Think carefully how this should be represented as data.

What to submit

You should submit your data definitions and examples in a file named IceCream.java

Problem 3: Traveling

We’ve been asked to help build a new medieval adventure game, Summer Is Coming. We’re trying to figure out the gameplay mechanics, so we’re starting with representations for travel around the game world. Players can live in three types of housing: a Hut, an Inn, and a Castle.

A Hut has a capacity and the current count of its population. The population must be less than the capacity.

An Inn has a name, capacity and the current count of its population as well as the number of stalls in its stable. The population must be less than the capacity.

A Castle has a name, the family-name of the owners, the current count of its population as well as the number of carriages it can hold in its carriage-house.

There are 2 types of transportation in this game:
  • Horse

  • Carriage

Each type of transportation should have a from and a to housing. Horses also have a name and a color (which you may represent using the color’s name). They can only go to an inn if there is room in the stables, but they can go to any hut or castle.

Carriages can only carry a limited supply of tonnage and only travel from Inns to Castles or vice versa. When they go to a Castle there must be room for them in the carriage house.

Name your examples horse1, carriage2, etc., and your examples class ExamplesTravel.

We’re placing a lot of restrictions on the data, such as the population being less than capacity, possible destinations of carriages, etc. However we aren’t (yet) actually enforcing these in the code. The ways to enforce these constraints will be further explored later in the semester. For now, you are expected to create examples that conform to these constraints.

What to submit

You should submit your data definitions and examples in a file named Travel.java