SENG2200 Programming Languages & Paradigms Assignment 2 Solved

SENG2200 Programming Languages & Paradigms 
Assignment 2

1. Objectives 
This assignment aims to build the understanding of Java programming in topics of interface, polymorphism, generics and iterator. A successful submission should be able to demonstrate a solution of the assignment tasks, with correct Java implementation and report.

 

2. Problem Statement 
The firm in Denman still believes that data structures that are hand-coded will run faster than those used from the Java libraries, and so this is still required for your container types.  However, once the true nature of generic structures was explained to them, they have decided that containers will use generic specifications and standard iterator interfaces.

 

NOTE: You can reuse the code from your Assignment 1 as much as possible. 

 

 

2.1 Written Report
As you design, write and test your solution, you are to keep track of and report on the following:  

1.     For each of the programs keep track of how much time you spend designing, coding and correcting errors, and how many errors you need to correct.

2.     Keep a log of what proportion of your errors come from design errors and what proportion from coding/implementation errors.

3.     Provide a (brief) design of how you would further extend your PA2 so that it specifically included Triangle and Square figures. Draw the UML class diagram for this new program (intricate detail not required). What attribute data do you need in each case?

4.     Investigate the mathematical structure of an Ellipse on the Cartesian plane. How would you model the Ellipse? How would you then calculate its area and originDistance()? How would this be incorporated into your program? Draw another UML class diagram to show this.

 

 

2.2 Point Class
The Point class should be exactly the same as for Assignment 1. (Please refer to Section 2.2 of Assignment 1, if needed.)

             

 

2.3 Redesign
In Assignment 1, we didn’t take much thought to realise that there are many shapes other than polygons (even when we remember that rectangles and squares are also polygons). To provide the program extensibility, you need to redesign in a completely different approach for below.

 

 

 

2.4 The Abstract Class - PlanarShape
Design and write an abstract PlanarShape class. It will have an abstract toString() method for printing results, an abstract area() method and an abstract originDistance() method. Because we need to compare PlanarShape objects, we also need to use (implement) the standard Comparable<T interface. 

PlanarShape has an ordering based on area() and originDistance()as previously was the case for Polygons. If any two PlanarShape objects have areas within 0.1% units of each other, then they are assumed to have equal area, in which case, the planar shape with the lower originDistance() takes precedence.   

 

 

2.5 Polygon Class
The Polygon class is similar to Assignment 1 but will require a re-design because of Section 2.3 and 2.4 (i.e you can reuse your code, but it will be changed somehow). A special thing about a Polygon now, is that it is a PlanarShape.

Input data specification for a polygon will be exactly the same as Assignment 1. The output format (i.e toString() method) will be  

POLY=[point0point1…pointn-2]: area_value 
For the area values, the format to be used is 6.2f.

 

2.6 Circle Class 
Design and write a Circle class. Circle object is specified by a Point which is the centre of the circle and a double type value r which is the radius of the circle. The area of a circle is the usual πr2. The originDistance() of a circle is given as the distance from the origin of the centre minus the radius (possibly negative). Its toString() method produces the string  

CIRC=[point0 r]: area_value 
Input data specification for a circle object is C x0 y0 r (E.g., C 5.1 4.0 3.2). For the radius values and the area values, the format to be used are 4.2f and 6.2f, respectively.

 

2.7 Semi-Circle Class 
Design and write a SemiCircle class. SemiCircle object is specified by a Point which is the centre of the base of the semicircle, and a second Point which specifies the point on the semi-circle at the end of the perpendicular to the base.  

The radius of the semi-circle is the length of the perpendicular vector, and so the area of the semi-circle is simply πr2/2.  

The originDistance() of a semi-circle is given as the distance from the origin of the closest of the two data points and the two base extremity points (x2, y2) and (x3, y3).

Its toString() method produces the string:  

SEMI=[point0 point1]: area_value 
Input data specification for a semi-circle object is S x0 y0 x1 y1 (E.g., S 4 3 5.1 4.2). For the area values, the format to be used is 6.2f.

 

  

𝑥2 = 𝑥0− |𝑦0−𝑦1|,       𝑦2 = 𝑦0 + |𝑥0−𝑥1|

𝑥3 = 𝑥0 + |𝑦0−𝑦1|,       𝑦3 = 𝑦0− |𝑥0−𝑥1|

 

 

 

2.8 Data Structure 
You are required to implement a circular doubly-linked list, using generics and iterators. A single sentinel node is also used to mark the head/tail of the list; the list class you will call LinkedList. It should contain methods to prepend() and append() items into the list and a means of taking items from the head of the list. It will not need a current item as a class member because any functionality requiring this should migrate to the iterator class for the LinkedList.

 

The LinkedList requires PlanarShape objects (references to them at least) to be the basis of the list, and we need to add type protection for this by way of a generic specification of the list and instantiation of the list so that it only allows <PlanarShape objects to be inserted and accessed. Your LinkedList must be Iterable and so you need to provide an iterator for your LinkedList class. This will only implement the standard iterator methods.

 

2.9 Sorting 
You are required to implement an insertInOrder(…) method to sort a linked list using insertion sort algorithm. It will need to properly use the comparable interface implementation of the compareTo<PlanarShape method from within the PlanarShape class.  

 

2.10 Required Processing 
•       Read input data specifications (until end of file, from standard input) and place them into an instance of your circular doubly-linked list, in input order.

•       Parse and store each “shape” specification. Design and implement factory pattern to create different types of objects. You do not have to worry about any of the data being missing, or out of order.

•       Then, you are to produce a second list, which contains the same set of Planar Shape objects, but this time, sorted into increasing area order.  

•       Output for your assignment is a complete print of both your lists, ie: the shapes in input order, and then the shapes in sorted order, listing the area of each shape in each case, as per the specification of toString() given above. The output should also be produced using iterators to visit the objects in the lists.

 

2.11 Input and Output 
All input (coming from standard input) will be from a user-defined text file. That is, your program should be able to read shapes from a text file. A sample test file is as follows (you should create one for self-testing before submission):

 

 P 5 4.0 0 4 8.1 7.2 8 7 3 9 0C 5.1 4.0 3.2     

 S 4 3   5.0 4.0 
 

All output is to the standard output. A sample output of the above input is as follows:

  Unsorted listSEMI=[(4.00 , 3.00)(5.00 , 4.00)]:  39.27  

 CIRC=[(5.10 , 4.00))  3.20]:  32.17 

 POLY=[(4.00 , 0.00)(4.00 , 8.10)(7.20 , 8.00)(7.00 , 3.00)(9.00 , 0.00)]:  27.66 Sorted list 

 POLY=[(4.00 , 0.00)(4.00 , 8.10)(7.20 , 8.00)(7.00 , 3.00)(9.00 , 0.00)]:  27.66 

 CIRC=[(5.10 , 4.00))  3.20]:  32.17 

  SEMI=[(4.00 , 3.00)(5.00 , 4.00)]:  39.27  
 

 

For input and output and formatting, you may only use Java libraries. If you feel you need extra libraries, you  can a) discuss in tutorial, or b) email Dan.

 

4. Submission  
Submission is through the Assessment tab for SENG2200 on Blackboard under the entry Assignment 2. If you submit more than once then only the latest will be graded. Every submission should be ONE ZIP file (not a .rar, or .7z, or etc) named c9999999.zip (where c9999999 is your student number) containing:

•       Assessment item cover sheet.

•       Report (PDF file): addresses the tasks in Section 2.1.

•       Program source files.  

Programming is in Java. Name your startup class PA2 (capital-P capital-A number-1), that is, the marker will compile your program with the command:  javac PA2.java 

…and to run your program with the command:  java PA2 test.dat 

…within a Command Prompt window.  

 

Note that test.dat is a placeholder; your program will have to handle different names and extensions for testing. 

If your program cannot be compiled and executed (incl. run-time errors) by using the above commands, you may receive ZERO mark without being examined. 

 

 

 

 

 

 

 

 

 

 

 

 

 

5. Marking Criteria 
This guide is to provide an overview of Assignment 2 marking criteria. It briefly shows the mark distribution. This guide is subject to adjustment without notice.

 

Program Correctness            

        • Comparable Interface              (5%)

        • Polymorphism                          (20%) 
o   Incl. required methods o Incl. factory pattern

o   If polymorphism concept has not been correctly implemented, you will significantly lose mark here.

        • Generics                                   (10%) 
o Your program should properly use “generics” concept in (at least) the required classes

        • Iterator                                     (20%)  
o Implementation of standard Iterator interface o Each required method implementation may have different marks.

        • Input/Output                            (10%) 
o   Your program should be able to correctly read text (shape) specifications.

o   Your program output should follow any format specified, e.g., 4.2f.

        • General                                    (15%) 
o   Incl. required general methods, such as area calculation and sorting.

o   OO design – your program should follow the basic principles of OO design, while you will NOT be marked specifically on the design.

Report                                                (10%) 

 

Miscellaneous                                    (10%) 

•       Code Format & Comments                                                     

Deductions 

•       Errors with filenames, submission, execution, mathematic results, and any other issue not covered above will attract penalties

 

* The mark for an assessment item submitted after the designated time on the due date, without an approved extension of time, will be reduced by 10% of the possible maximum mark for that assessment item for each day or part day that the assessment item is late. Note: this applies equally to week and weekend days. 

** The assignment (code and report) will be checked for plagiarism. A plagiarized assignment will receive a zero mark and will be reported to SACO.