COMP9024 20T2 – Assignment 2/8/20, 12:47
COMP9024 20T2 Assignment Data Structures and Algorithms
goNSW
Change Log
We may make minor changes to the spec to address/clarify some outstanding issues. These may require minimal changes in your design/code, if at all. Students are strongly encouraged to check the change log regularly.
Version 1: Released on 10 July 2020
Objectives
The assignment aims to give you more independent, self-directed practice with
advanced data structures, especially graphs graph algorithms
asymptotic runtime analysis
Admin
Marks 3 marks for stage 1 (correctness) 5 marks for stage 2 (correctness) 2 marks for stage 3 (correctness)
1 marks for complexity analysis 1 mark for style ———————
Total: 12 marks
Due 11:00:00am on Monday 3 August (week 10) Late 2 marks (16.67%) off the ceiling per day late
(e.g. if you are 25 hours late, your maximum possible mark is 8)
Aim
Your task is to write a program goNSW.c for finding an optimal public transport connection that takes into account a given departure time and user preferences.
Input
Network
Your program should start by prompting the user to input a positive number n followed by n lines, each containing the name of a train station or bus/light rail stop. An example is:
prompt$ ./goNSW
Enter the total number of stops on the network: 5
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COMP9024 20T2 – Assignment 2/8/20, 12:47
Chinatown
Central
Kensington
UNSW
Wynyard
You may assume that:
The input is syntactically correct.
Names require no more than 31 characters and will not use any spaces. No stop name will be input more than once.
Hint:
To read a single line with a stop name you may use:
scanf(“%s”, stop); // stop is a character array (= string variable)
Schedules
Next, your program should ask the user for the number m of busses, trains and light rail vehicles running during a day, followed by m schedules. Each schedule requires the number of stops, k≥2, followed by k*2 lines of the form:
meaning that passengers can get on or off at that time (hh – hour, mm – minute) at that stop. An example is:
Enter the number of schedules: 2 Enter the number of stops: 5 1640
UNSW
1645
Kensington
1705
Central
1708
Chinatown
1715
Wynyard
Enter the number of stops: 2 1645
UNSW
1700
Central
You may assume that:
The input is syntactically correct: 4 digits, then a new line with the name of a stop.
hhmm
stop-name
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COMP9024 20T2 – Assignment 2/8/20, 12:47
All times are valid and range from 0000 to 2359.
Stops are input in the right (temporal) order.
There are no overnight connections: Each bus, light rail or train will reach its final stop before midnight.
Only valid stops that have been input before will be used.
Queries
After reading the transportation network, your program should prompt the user to search for a connection:
From: UNSW
To: Wynyard Depart at: 1630
Again you may assume that the input is correct:
Only stops that have been entered before are used and a valid time is given. The two stops will not be the same.
If the user inputs “done,” then your program should terminate:
From: done
Thank you for using goNSW. prompt$
Stage 1 (3 marks)
For stage 1, you should demonstrate that you can read the input and generate a suitable data structure.
For this stage, all test cases will only use queries (From, To, DepartAt) for which there is only one bus, train or light rail service connecting From and To ; and
this is guaranteed to depart on, or after, the requested time, DepartAt .
Hence, all you need to do for this stage is find and output this direct connection, including all stops along the way and the arrival/departure times. Here is an example to show the desired behaviour of your program for a stage 1 test:
prompt$ ./goNSW
Enter the total number of stops on the network: 7 Wynyard
QVB
Central
Kensington
UNSW
Glebe
Broadway
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COMP9024 20T2 – Assignment 2/8/20, 12:47
Enter the number of schedules: 2 Enter the number of stops: 5 0945
Wynyard
0950
QVB
1000
Central
1022
Kensington
1027
UNSW
Enter the number of stops: 2 1459
Broadway
1518
Glebe
From: Broadway To: Glebe Depart at: 0950
1459 Broadway
1518 Glebe
From: QVB
To: Kensington Depart at: 0950
0950 QVB
1000 Central
1022 Kensington
From: done
Thank you for using goNSW. prompt$
Stage 2 (5 marks)
For stage 2, you should extend your program for stage 1 such that it always finds, and outputs, a connection between From and To that
departs on, or after, the requested time DepartAt ; and arrives as early as possible.
You should assume that:
Changing takes no time: Passengers arriving at a stop can get onto any other train, bus or light rail service that leaves that stop at the same time or later.
In all test scenarios there will be at most one connection that satisfies all requirements.
If there is no connection, the output should be:
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COMP9024 20T2 – Assignment 2/8/20, 12:47
Here is an example to show the desired behaviour and output of your program for a stage 2 test:
prompt$ ./goNSW
Enter the total number of stops on the network: 5 Central
Eastwood
Redfern
Strathfield
Wynyard
Enter the number of schedules: 2
Enter the number of stops: 4
0915
Eastwood
0935
Strathfield
1002
Redfern
1017
Wynyard
Enter the number of stops: 3
1005
Redfern
1010
Central
1015
Wynyard
From: Eastwood To: Wynyard Depart at: 0910
0915 Eastwood
0935 Strathfield
1002 Redfern
Change at Redfern
1005 Redfern
1010 Central
1015 Wynyard
From: Eastwood To: Redfern Depart at: 0920
No connection found.
From: done
Thank you for using goNSW.
Stage 3 (2 marks)
No connection found.
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COMP9024 20T2 – Assignment 2/8/20, 12:47
For stage 3, you should extend your program for stage 2 such that:
If there are two or more valid connections with the same earliest arrival time, choose the one with the latest departure time.
Here is an example to show the desired behaviour and output of your program for a stage 3 test:
prompt$ ./goNSW
Enter the total number of stops on the network: 5 Chinatown
Central
Kensington
UNSW
Wynyard
Enter the number of schedules: 2
Enter the number of stops: 5
1640
UNSW
1645
Kensington
1705
Central
1708
Chinatown
1715
Wynyard
Enter the number of stops: 2
1645
UNSW
1700
Central
From: UNSW
To: Wynyard Depart at: 1630
1645 UNSW
1700 Central
Change at Central
1705 Central
1708 Chinatown
1715 Wynyard
From: done
Thank you for using goNSW.
Complexity Analysis (1 mark)
Your program should include a time complexity analysis for the worst-case asymptotic running time of your program, in Big-Oh notation, depending on the size of the input:
1. the number of stops, n
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COMP9024 20T2 – Assignment 2/8/20, 12:47
2. the number of schedules, m
3. the maximum number k of stops on a single train, bus or light rail line.
Hints
If you find any of the following ADTs from the lectures useful, then you can, and indeed are encouraged to, use them with your program:
linked list ADT : list.h, list.c
stack ADT : stack.h, stack.c
queue ADT : queue.h, queue.c
priority queue ADT : PQueue.h, PQueue.c graph ADT : Graph.h, Graph.c
weighted graph ADT : WGraph.h, WGraph.c
You are free to modify any of the six ADTs for the purpose of the assignment (but without changing the file names). If your program is using one or more of these ADTs, you should submit both the header and implementation file, even if you have not changed them.
Your main program file goNSW.c should start with a comment: /* … */ that contains the time complexity of your program in Big-Oh notation, together with a short explanation.
Testing
We have created a script that can automatically test your program. To run this test you can execute the dryrun program that corresponds to this assignment. It expects to find, in the current directory, the program goNSW.c and any of the admissible ADTs (Graph,WGraph,stack,queue,PQueue,list) that your program is using, even if you use them unchanged. You can use dryrun as follows:
prompt$ 9024 dryrun goNSW
Please note: Passing dryrun does not guarantee that your program is correct. You should
thoroughly test your program with your own test cases.
Submit
For this project you will need to submit a file named goNSW.c and, optionally, any of the ADTs named Graph,WGraph,stack,queue,PQueue,list that your program is using, even if you have not changed them. You can either submit through WebCMS3 or use a command line. For example, if your program uses the Graph ADT and the queue ADT, then you should submit:
prompt$ give cs9024 assn goNSW.c Graph.h Graph.c queue.h queue.c Do not forget to add the time complexity to your main source code file goNSW.c.
You can submit as many times as you like — later submissions will overwrite earlier ones. You can check that your submission has been received on WebCMS3 or by using the following command:
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COMP9024 20T2 – Assignment 2/8/20, 12:47
prompt$ 9024 classrun -check assn Marking
This project will be marked on functionality in the first instance, so it is very important that the output of your program be exactly correct as shown in the examples above. Submissions which score very low on the automarking will be looked at by a human and may receive a few marks, provided the code is well-structured and commented.
Programs that generate compilation errors will receive a very low mark, no matter what other virtues they may have. In general, a program that attempts a substantial part of the job and does that part correctly will receive more marks than one attempting to do the entire job but with many errors.
Style considerations include:
Readability
Structured programming Good commenting
Plagiarism
Group submissions will not be allowed. Your program must be entirely your own work. Plagiarism detection software will be used to compare all submissions pairwise (including submissions for similar projects in previous years, if applicable) and serious penalties will be applied, including an entry on UNSW’s plagiarism register.
Do not copy ideas or code from others
Do not use a publicly accessible repository or allow anyone to see your code, not even after the deadline
Please refer to the on-line sources to help you understand what plagiarism is and how it is dealt with at UNSW:
Plagiarism and Academic Integrity UNSW Plagiarism Policy Statement UNSW Plagiarism Procedure
Help
See FAQ for some additional hints.
Finally …
Have fun! Michael
Reproducing, publishing, posting, distributing or translating this assignment is an infringement of copyright and will be referred to UNSW Conduct and Integrity for action.
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