ENGG1340 / COMP2113, Assignment 3
Due Date: Nov 30, 2020 23:59
If you have any questions, please post to the Moodle discussion forum on Assignment 3.
General Instructions
Problem 1: Game of Elimination in C++ (45 marks)
Problem 2: STL - Log Analyzer (50 marks)
Total marks: 100 marks
5 marks for proper code comments, indentation and use of functions
95 marks for program correctness
General Instructions
Read the instructions in this document carefully.
In this assignment you will solve 2 tasks and a tester would automatically test your submitted program. So if your submitted
files and program outputs do not conform to our instructions given here, your programs cannot be evaluated and you will risk
losing marks totally.
Sample test cases are provided with each task in this document. Note that the test cases may or may not cover all boundary
cases for the problem. It is also part of the assessment whether you are able to design proper test cases to verify the
correctness of your program. We will also use additional test cases when marking your assignment submission.
Input and output format
Your C++ programs should read from the standard input. Also, your program output should be printed through the standard
output. If you failed to follow the instructions, the tester may not able to give a score for your program. Additionally, you
should strictly follow the sample output format (including space, line breaker, etc.), otherwise, your answer might be
considered as wrong.
How to use the sample test cases
Sample test cases in text file formats are made available for you to check against your work. Here's how you may use the
sample test cases. Take Problem 2 test case 3 as an example. The sample input and the expected output are given in the files
input2_3.txt and output2_3.txt , respectively. Suppose that your program is named "2", do the followings at the
command prompt of the terminal to check if there is any difference between your output and the expected output.
./2 < input2_3.txt > myoutput.txt
diff myoutput.txt output2_3.txt
Testing against the sample test cases is important to avoid making formatting mistakes. The additional test cases for
grading your work will be of the same formats as given by the sample test cases.
Coding environment
You must make sure that your program can compile, execute and generate the required outputs on our standard environment,
namely, the gcc C++11 environment we have on the CS Linux servers (academy*). As a programmer/developer, you should
always ensure that your code can work perfectly as expected on a target (e.g., your client's) environment, not only on yours.
While you may develop your work on your own environment, you should always try your program (compile & execute & check
results) on our standard environment before submission.
Make sure the following compilation command is used to compile your programs:
g++ -pedantic-errors -std=c++11 [yourprogram].cpp
Submission
Name your C++ programs as the following table shows and put them together into one directory. Make sure that the folder
contains only these source files ( *.cpp ) and no other files. Compress this directory as a [uid].zip file where [uid] is
your university number and check carefully that the correct file have been submitted. We suggest you to download your
submitted file from Moodle, extract them, and check for correctness. Resubmission after the deadline is not allowed.
A maximum of 5 marks will be deducted if you fail to follow the submission instructions strictly.
Note that code template for Problem 2 is provided, and you should base your work on it.
Problem Code files provided? Files to Submit
1 Create your own 1.cpp 1.cpp
2 2.cpp 2.cpp
Late submission
If submit within 3 days after the deadline, 50% deduction. After that, no mark.
Evaluation
Your code will be auto-graded for technical correctness. In principle, we use test cases to benchmark your solution, and you
may get zero marks for not being able to pass any of the test cases. Normally partial credits will not be given for incomplete
solution, as in many cases the logic of the programs are not complete and an objective assessment could be difficult.
However, your work may still be considered on a case-by-case basis during the rebuttal stage.
Academic dishonesty
We will be checking your code against other submissions in the class and from the Internet for logical redundancy. Please be
reminded that no matter whether it is providing your work to others, assisting others to copy, or copying others will all be
considered as committing plagiarism and we will follow the departmental policy to handle such cases. Please refer to the
course information notes for details.
Discussion forum
You are not alone! If you find yourself stuck on something, post your question to the course forum. We want this assignment
to be rewarding and instructional, not frustrating and demoralizing. But we don’t know when or how to help unless you ask.
Please be careful not to post spoilers. Please don’t post any code that is directly related to the assignments. However you
are welcome and encouraged to discuss general ideas on the discussion forums. If you have any questions about this
assignment you should post them in the discussion forums.
Problem 1: Game of Elimination in C++
Consider a prize to be awarded to a winner among n > 0 contestants by a game of elimination. The n contestants first line up
in a line, and are assigned the numbers 1 to n one by one.
The host of the game then decides on an integer k > 1, and starting from contestant 1, the host counts k contestants down
the line and eliminates the k-th contestants from the circle. He then continues to count for another k contestants, and
eliminates the k-th contestants from the line. When he counts to the end of line, he will continue counting from the beginning
of the line. This process repeats until there is only one contestant remains who will be the winner of the prize.
For example, if n = 7 and k = 3,
The initial line: 1234567, count to 3 and contestant 3 is eliminated
Line now becomes: 124567, continue counting from 4 and contestant 6 is eliminated
Line now becomes: 12457, continue counting from 7 and contestant 2 is eliminated
Line now becomes 1457, continue counting from 4 and contestant 7 is eliminated
Line now becomes 145, continue counting from 1 and contestant 5 is eliminated
Line now becomes 14, continue counting from 1 and contestant 1 is eliminated
Winner is contestant 4
Write a C++ program which implements a circular linked list (see Module 8 Guidance Notes p.92) to determine which
contestant will win the prize.
Program input. Two input numbers n and k (n > 0 and k > 1).
Program output. The winner of the game.
Requirement: You will need to implement the circular linked list on your own, i.e., you may NOT use any STL containers or
external linked list libraries.
Idea:
Use the program build_list_forward.cpp of Module 8 as a basis for your work. The program essentially has built a
linked list; to turn it into a circular linked list, you just need to point the next pointer of the last node to the head of the list.
You will need to build a circular linked list containing the numbers 1 to n
You will then need to traverse through the linked list and remove a node once you have traversed for k nodes.
After removing a node, you should check if there remains only one node in the list. If yes, the winner is identified.
Remember to free all memories used by the linked list before the program terminates.
Hint:
Study carefully build_list_forward.cpp and build_list_sorted.cpp of Module 8. They should contain the main
building blocks for you to finish this task.
It is expected that you will only need to write no more than 20-30 lines of additional code, after reusing the appropriate
codes in build_list_forward.cpp and build_list_sorted.cpp . Of course, it is OK if you write more than that.
Sample Test Cases
User inputs are shown in blue.
Problem 2: STL - Log Analyzer
You are provided with a template program 2.cpp . Complete the program and the program will read and process a web log
data file from user input ( cin ). The program will then print out the 5 most popular pages, and the 5 most active users and the
corresponding pages they have visited.
The log file consists of records of three types, each record occupies exactly one line. Here is the format of these three types
of record:
Page record: PAGE
User record: USER
Visiting record: VISIT
A page record represents a page on the web server. A user record represents a user that accesses the system. A visiting
record represents a visit by the user indicated by the most recent user record. Here is a sample data file:
PAGE 1288 /library
PAGE 1282 /home
USER 20686
VISIT 1288
VISIT 1282
USER 20687
VISIT 1288
In this case, we have 2 pages ( /library and /home ) on the server. Two users have accessed the server, one (#20686)
visiting 2 pages ( /library and /home ) and the other (#20687) visiting 1 page ( /library ).
You can assume the followings regarding the data file:
The data file always consists of the three types of records only
The page ids are unique across all PAGE records
The user ids are unique across all USER records
The page ids are unique across all VISIT records of a user
VISIT records will only appear after the first USER record
The page id in a VISIT record appears only after its corresponding PAGE record
There will be at least 5 users and 5 pages
The followings have been implemented for you:
A Page structure, each Page object consists of the id, path and a counter to count the number times it is being visited
struct Page {
int id;
string path;
int counter;
Page(int id, string path) {
this->id = id;
this->path = path;
counter = 0;
};
};
A STL vector for organizing the Page objects
vector
pages;
A User structure, each User object consists of the id and the pages the user visited
struct User {
int id;
vector visits;
User(int id) {
this->id = id;
};
void add_visit(int page_id) {
...
};
int size() const {
return visits.size();
};
void print_visits() {
...
}
};
A STL vector for organizing the User objects
vector users;
A function to overload < operator for the comparison of 2 pages based on their ids
bool operator<(const Page & a, const Page & b) {
return (a.id < b.id);
};
You are required to complete the missing functions in the template program to make it work.
Note: The functions Page() and User() in the structs Page and User above are called struct constructors. Refer to
Module 10 "C Programming (Part 3)" for the discussion on the struct constructor functions. It works the same in C++.
Sample Test Cases
You are provided with 4 sample test cases. We will use the first test case and detail the test run below.
Assume we have input2_1.txt in the current directory. If we run the program like this (assuming that we are working on
Linux):
$ g++ -pedantic-errors -std=c++11 2.cpp -o 2
$ ./2 < input2_1.txt
The program will print:
*** 5 most popular pages ***
36:/msdownload
32:/ie
17:/products
17:/search
13:/sitebuilder
*** 5 most active users ***
23:10068
- /activeplatform
- /activex
- /automap
- /frontpage
- /gallery
- /ie
- /intdev
- /isapi
- /java
- /msdownload
- /musicproducer
- /office
- /promo
- /sbnmember
- /search
- /sitebuilder
- /spain
- /vbasic
...
[snipped]
...
11:10019
- /athome
- /clipgallerylive
- /games
- /isapi
- /kb
- /logostore
- /msdownload
- /msoffice
- /ntserver
- /products
- /search
Note:
If two pages are equally popular, the pages are ordered lexicographically.
If two users visit the same number of pages, the users are ordered by their id ascendingly.
The list of pages a user visit must be printed in ascending order.
You can choose not to use the provided template program and implement in your own way. However, your program must
contain the provided Page and User structures and use STL vectors for storage.
Once again, you MUST use STL vectors in your program. Your program will be checked and your score will be 0 if we find
that you use traditional arrays to store pages and users in your implementation.