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Assignment Logistics |
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Assignment Logistics |
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The assignment aims to give you more independent, self-directed practice with
| Marks | 3 marks for stage 1 (correctness)
4 marks for stage 2 (correctness) 3 marks for stage 3 (correctness) 1 mark for complexity analysis 1 mark for style ——————— Total: 12 marks | |
| Due | 11:00:00am on Monday 14 November (week 10) | |
| Late | 5% reduction per day late, capped at 5 days (= 120 hours)
(e.g. if you are 25 hours late, your mark will be reduced by 1.2 marks) |
Your task is to write a program logistics.c to help a company determine the minimum number of distribution centres so that all cities are within a maximum distance from at least one distribution centre.
Your program should start by prompting the user to input a positive number n followed by n lines, each containing the name of a city. An example is:
./logistics Enter the number of cities on the distribution network: 3 Berlin Frankfurt Hamburg
You may assume that:
Hint: To read a single line with the name of a city you may use:
scanf("%31s", city); // city is a character array (= string variable)
(Originally it said ...%32..., which can be used also provided the string variable is large enugh, i e. 32+1 bytes long.)
Next, your program should ask the user for the number of roads, m, then prompt the user to input m roads. Each road requires the name of a city (from), the name of another city (to) and the distance (in km). An example is:
Enter the number of roads: 2 Enter the name of a city: Hamburg Enter the name of a city: Frankfurt Enter the distance: 492 Enter the name of a city: Berlin Enter the name of a city: Hamburg Enter the distance: 289
All roads are directional, that is, from the first city to the second city.
You may assume that:
Finally, your program should prompt the user to input the required maximum distance to a distribution centre:
Enter the required maximum distance: 350
Again, you may assume that the input is correct (a non-negative integer).
For stage 1, you should demonstrate that you can read the input and generate a suitable data structure.
For this stage, all test cases are guaranteed to satisfy the following conditions:
The required maximum distance is large enough so that the unique optimal solution is to have one distribution centre, in the first city.
Hence, all you need to do for this stage is to
./logistics Enter the number of cities on the distribution network: 3 Berlin Frankfurt Hamburg Enter the number of roads: 2 Enter the name of a city: Hamburg Enter the name of a city: Frankfurt Enter the distance: 492 Enter the name of a city: Berlin Enter the name of a city: Hamburg Enter the distance: 289 Enter the required maximum distance: 1000 Hubs: Berlin Routes: Berlin: Berlin 0 Frankfurt: Berlin - Hamburg - Frankfurt 781 Hamburg: Berlin - Hamburg 289
For stage 2, you should extend your program for stage 1 such that it finds an optimal solution, that is, a minimal set of distribution centres (hubs) so that each city is within the maximum required distance from one of the centres.
For this stage, all test cases are guaranteed to satisfy the following condition:
./logistics Enter the number of cities on the distribution network: 3 Berlin Frankfurt Hamburg Enter the number of roads: 2 Enter the name of a city: Hamburg Enter the name of a city: Frankfurt Enter the distance: 492 Enter the name of a city: Berlin Enter the name of a city: Hamburg Enter the distance: 289 Enter the required maximum distance: 350 Hubs: Berlin, Frankfurt Routes: Berlin: Berlin 0 Frankfurt: Frankfurt 0 Hamburg: Berlin - Hamburg 289
For stage 3, you should extend your program for stage 2 such that:
If there are two or more solutions with the same minimum number of distribution centres, you should output all minimal solutions, in alphabetical order of the distribution centres.
For example, if {Berlin,Hamburg} and {Berlin,Frankfurt} are two optimal solutions, then the first solution in your output should be: Berlin, Frankfurt.
Here is an example to show the desired behaviour and output of your program for a stage 3 test:./logistics Enter the number of cities on the distribution network: 3 Berlin Frankfurt Hamburg Enter the number of roads: 2 Enter the name of a city: Hamburg Enter the name of a city: Frankfurt Enter the distance: 492 Enter the name of a city: Berlin Enter the name of a city: Hamburg Enter the distance: 289 Enter the required maximum distance: 500 Hubs: Berlin, Frankfurt Routes: Berlin: Berlin 0 Frankfurt: Frankfurt 0 Hamburg: Berlin - Hamburg 289 Hubs: Berlin, Hamburg Routes: Berlin: Berlin 0 Frankfurt: Hamburg - Frankfurt 492 Hamburg: Hamburg 0
Hint: For each solution, you only need to output one shortest route for each city. There will be no test cases in which a city is at equal distance from two distribution centres, or where there are two different shortest routes from a hub to a city.
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 number n of cities.
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:
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 logistics.c should start with a comment: /* … */ that contains the time complexity of your program in Big-Oh notation, together with a short explanation.
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 logistics.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:
9024 dryrun logistics
Please note: Passing dryrun does not guarantee that your program is correct. You should thoroughly test your program with your own test cases.
give cs9024 assn logistics.c Graph.h Graph.c queue.h queue.c
Do not forget to add the time complexity to your main source code file logistics.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:9024 classrun -check assn
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 multiple compilation or runtime errors.
Style considerations include:
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, particularly in the case of repeat offences.
Please refer to the on-line sources to help you understand what plagiarism is and how it is dealt with at UNSW:
Reproducing, publishing, posting, distributing or translating this assignment is an infringement of copyright and will be referred to UNSW Conduct and Integrity for action.