CSE2/CSE5ALG代做、代写Data Structures、Java代写、Java程序调试

日期：2019-05-21 08:47

CSE2/CSE5ALG– Algorithms and Data Structures – 2019

Assignment – Part 2

Assessment: This part 2 of the assignment is worth 20% of the final mark for this subject.

Due Date: Monday 27 May 2019 at 10:00 AM

Delays caused by computer downtime cannot be accepted as a valid reason for a late submission

without penalty. Students must plan their work to allow for both scheduled and

unscheduled downtime. Penalties are applied to late assignments, accepted up to 5 days after the

due date only. Please make the submission after Friday 10 May 2019 at 10:00 AM.

Copying, Plagiarism: Plagiarism is the submission of somebody else’s work in a manner that

gives the impression that the work is your own. The Department of CS and IT treats academic

misconduct seriously. When it is detected, penalties are strictly imposed.

Submission Details: Submit all the Java files that are required for the tasks described in this

handout. The code has to run under Unix on the latcs8 machine. You submit your files from your

latcs8 account. Make sure you are in the same directory as the files you are submitting. Submit

each file separately using the submit command. For example, for the file called (say)

WordMatch.java, use command:

submit ALG WordMatch.java

After submitting the files, you can run the following command that lists the files submitted from

your account:

verify

You can submit the same filename as many times as you like before the assignment deadline; the

previously submitted copy will be replaced by the latest one.

Testing Platform: While you are free to develop the code for this assignment on any operating

system, your solution must run on the latcs8 system. We should be able to compile your classes

with the simple command javac *.java, and execute your programs with a simple command,

e.g. java WordMatch in1.txt out1.txt in2.txt out2.txt.

Return of Assignment: Assignments will be returned within three weeks of the due date.

Students will be notified by email and via the CSE2/CSE5ALG website when marking sheets are

available for collection.

Assignment Objectives

To understand various data structures and searching and sorting techniques;

To analyse these techniques in relation to a particular problem;

To implement these techniques within a Java program.

1

Background

As described in the handout for Part 1, the overall aim of the assignment is to develop a program

to build a lexicon and to find the words that match certain patterns.

Whereas for Part 1 we are only concerned with the correctness of the program, for Part 2 we are

concerned with the efficiency. More specifically, you are required to do the tasks described below.

Besides the information given in the tasks below, please refer to Part 1 of the Assignment for any

other information you need.

Task 1 (80 marks)

Write a Java program called WordMatch.java. This program takes four command-line arguments.

For example:

java WordMatch in1.txt out1.txt in2.txt out2.txt

1. The first is the name of a text file that contains the names of the text files from which the

words are to be read to build the lexicon (The aim of this argument is to specify the input

files)

2. The second is the name of the text file to which the words in the lexicon are to be written

(The argument specifies the file that contains the words and their neighbors in the lexicon)

3. The third is the name of a text file that contains a number of matching patterns, one per line

(The aim of this argument is to provide the matching patterns)

4. The fourth is the name of the text file that contains the result of the matching for the given

patterns (The argument specifies the file that contains the result)

For this version, the efficiency with which the program performs various operations is a major

concern.

For example, the files read in can be quite long and the lexicon of words can grow to be quite

lengthy. Time to insert the words will be critical here and you will need to carefully consider

which algorithms and data structures you use.

You can use any text files for input to this program. A good source of long text files is at the

Gutenberg project (www.gutenberg.com) which is a project aimed to put into electronic form

older literary works that are in the public domain. The extract from Jane Austen’s book Pride and

Prejudice used as the sample text file above was sourced from this web site. You should choose

files of lengths suitable for providing good information about the efficiency of your program.

A selection of test files have been posted on LMS for your efficiency testing. You can consider

additional test files if you wish.

As expected, the definition of a word, and the content of a query’s result and display of this result

are exactly the same as what described in Part 1.

All the Java files must be submitted. The program will be marked on correctness and efficiency.

Bad coding style and documentation may have up 5 marks deducted.

With the exceptions of ArrayList and LinkedList, you are not permitted to use any of

the classes in the Java Collections Framework, e.g. TreeMap, HashMap, Collections,

Arrays.

2

Task 2 - Report (20 marks)

Write a report about the WordMatch program and the classes that support it. The report has the

following sections:

Section 1: In this section, describe the classes that you implement for Task 1. For each class,

list and briefly describe its attributes and methods.

Section 2: In this section,

(a) Identify what you consider to be the main issues in the effort to make the program run

efficiently; for example, what subtasks you think could be costly in terms of execution

time

(b) Point out the techniques/features that you have used to address those issues

Section 3: In this section, explain how you test the functional correctness of your program.

Section 4: In this section, explain how you test the efficiency of your program. Make sure you

present quantitative information about its efficiency.

In the report, as well as in every Java class, you must include your student ID and name, and

the subject: CSE2ALG or CSE5ALG. Up to 5 marks can be deducted if these details are missing

How to submit the report: The report should be a file named Task2.pdf or Task2.docx. The

pdf format is the preferred one. Submit the report file, e.g. submit ALG Task2.pdf

Task 3 (Optional)

Develop a solution for the puzzle in which you are given two words, and you need to find a

sequence of words to transform the first word into the second by changing one letter at a time.

The key idea is to represent the list of words of the same length as a graph in which each node

represents a word, and two nodes are connected by an edge if the two associated words differ from

each other only by one letter. Thus, the solution would involve algorithms on graphs which we are

yet to cover.

Note: This optional work should NOT be attempted until all other tasks have been successfully

completed. Good attempts at these extensions are worth up to an additional 10% of the mark for

Part 2. However, it is not possible to end up with more than 100% for the total mark of Part 2.

3

Task 4 (For CSE5ALG students only)

Consider the B-trees of order M . Assume that we have the following result, which we will refer

to as Lemma 1.

Lemma 1: The barest B-tree of height H contains N = 2K H 1 elements, where 

Determine the upper bound for a B-tree of order 21 which has 1, 000, 000 = 106

elements.

You must give an integer value as the upper bound of the B-tree.

You are not allowed to use the result given in the lecture regarding the upper bound for Btree’s

height. Instead, you must work out the answer using Lemma 1 above.

Note: The total mark for Part 2 will be 100 for CSE2ALG students and 110 (100 + 10 for Task

4) for CSE5ALG students. The percentage of contribution to the final will be the same.