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KIT205 Data Structures and Algorithms
Assignment 1: Data Structures
Due: 26th April, 11:55pm
Introduction
You work for an online marketing company that manages a number of store loyalty programs.
You have been asked to develop some software to manage the customer database. You
decide to develop a prototype solution to test the performance of different data structures
and algorithms.
The company manages the program for several stores, but this number is not expected to
grow beyond a few dozen. More importantly, each program may have many thousands
(perhaps even millions) of customers; and, as a result of aggressive cross-marketing, many of
these customers are subscribed to multiple loyalty programs. Your software needs to provide
the following functions:
- Subscribe: This function will prompt the user for a customer id and loyalty program
name. If this data does not already exist in the database, it will be added. A
subscription will then be added for this customer and program. - Unsubscribe: This function will prompt the user for a customer id and loyalty program
name. The function will then remove this subscription but will not remove customers
or loyalty programs from the database, even if they have no subscriptions. - Print Summary: This function will print a line for each loyalty program, with each line
containing the name of the program followed by the number of subscribed customers. - Print Subscribers: This function will prompt the user for the name of a loyalty
program, then print an ordered list of customer ids for all subscribers to this program,
each one on a separate line. - Print Subscriptions: This function will prompt the user for a customer id, then print all
of the loyalty that this customer is subscribed to.
It is very important that access to data is very fast since many operations may occur each
second. This will be especially important when dealing with customers since the number of
customers may be very large and insert, delete, and find operations will be very common.
Initially, you decide to test performance using a combination of binary search trees, linked lists
and arrays, but you would like to test an AVL tree as well. For preliminary testing, you decide
that only the customer ids and loyalty program names will be stored.
Assignment Specification – Part A
For this part of the assignment you will select appropriate linked list, BST, and array data
structure to implement the four operations. Part of the assignment task is to use these data
structures in an efficient way. Your implementations of list and BST data structures MUST be
based on the definitions used in lectures and tutorials as given below.
typedef struct listNode{
int data;
struct listNode *next;
} *ListNodePtr;
typedef struct list {
ListNodePtr head;
} List;
typedef struct bstNode {
int data;
struct bstNode *left;
struct bstNode *right;
} *BSTNodePtr;
typedef struct bst {
BSTNodePtr root;
} BST;
These data structures will need to be modified to support the customer and loyalty program
information, which will be stored as long ints and strings. You will also need to add crossreferences
between the data structures to represent subscriptions. These may be one-way
references – i.e. a customer might have references to the programs they are subscribed to,
but the programs might not have references to the subscribed customers, or vice versa.
The ListNodePtr and List definitions and (modified) linked list functions must be placed in
files list.h and list.c. The BSTNodePtr and BST definitions and (modified) BST functions
must be placed in files bst.h and bst.c.
All remaining code should be placed in a file called main.c that contains the main function
and program logic. This file will contain separate functions for each of the four operations
listed in the introduction, as well as a fifth function to handle termination. Other functions
may be added if required.
Program I/O
All interactions with the program will be via the console. Operations 1-4 will be selected by
typing 1-4 at the command prompt. Quitting the application will be selected by typing 0. For
example, the following input sequence would subscribe the customer‘123’to the loyalty
program‘abc’, and then quit:e input only, not the program response (if any). You are free
to add prompts to make the application more user friendly, but this will not be assessed
(although it may be useful).
Program output in response to operations 3 and 4, should be as minimal as possible. You may
print a header if you wish, but this should be followed by one record per line with spaces
separating data. For example, in response to operation 3, the output might be:
Current subscriptions:
abc 32
def 0
ggg 10236
I/O Restrictions
You may assume that all input will always be in the correct format and contain no logical
errors.
Commands will always be in the range 0-4
Loyalty program names will always be strings less than 100 characters long and may
contain any alpha-numeric characters excluding spaces
Customer ids will always be positive integers in the range 0-999999999
The user will never attempt to print data for a non-existent loyalty program
The user will never attempt to print data for a non-existent customer
Memory Management
Loyalty program names should be stored in appropriately size dynamically allocated memory.
Names will always be less than 100 characters long. For example, the program name“abcdef”
would be stored in a char string of length 7.
Unsubscribing from a program may require you to free memory for that subscription (but not
for the customer or program itself). The quit function should free all dynamically allocated
memory.
Solution Requirements
You must develop a reasonably time efficient solution, but you also want to keep the code
clean and simple to make your code easier to modify and maintain (a computer scientist called
Donald Knuth, famously said that“premature optimisation is the root of all evil”).
Remember that, while the number of customers may be large, the number of loyalty programs
is expected to be relatively small.
So, to score full marks your solution must:
utilise at least one linked list and at least one bst
strings must be stored in appropriately sized dynamically allocated memory
the memory for all data structures should be freed when the data is no longer
required
If the number of customers is C and the number of loyalty programs is L then:
o Op 1 should be O(L + log C)
o Op 2 should be O(L + log C)
o Op 3 should be O(L * C)
o Op 4 should be O(L + C)
o Op 5 should be O(L * log C)
Note: A clever implementation might be able to achieve a better Big O for some of these
operations, but that is not required to achieve full marks on this assignment. You will not
receive extra marks for an implementation that achieves better performance.
Also note that the following work would get close to a pass mark:
BST and linked list code implemented correctly as per tutorial work
Evidence that you have made a sensible choice about how to use the data structures
(this could be determined from code comments or variable names, that make it clear
what choices you have made)
BST and linked list code adapted to store customers and loyalty programs (node
definitions only – functions don’t need to be correctly adapted)
A working main loop (calls functions when options are selected, functions collect
required input, but may not do anything with that input, exits without errors)
A solid attempt to get BST and linked list functions working in this context (with the
main loop and adapted data structures)
It is best to submit a program that compiles and runs without errors, even if the program
doesn’t do anything. If you have added new code that breaks you program, comment this
code out before submitting (and add an explanation) so that the marker can easily see what
you have completed. After running your program, the marker will then check the code to
determine what else you have attempted. Code that doesn’t compile or crashes is extremely
difficult to mark, and the marker may be forced to give you less marks if they are unable to
confirm what is working (they have very limited time to fix bugs).
Assignment Specification – Part B
This part of the assignment should only be attempted once you have a fully implemented and
thoroughly tested solution to part A. It would be better to submit a complete part A and no
part B than to submit a partially complete part A and part B. (If you look at the marking sheet
below, you will see that this part is worth at most 15%)
The requirements for this part of the assignment are exactly the same as for part A except that
an AVL tree must be used, rather than a BST. The AVL code should be placed in bst.h and
bst.c, with AVL functions added to these two files (you may also need to modify the node
definition, but this should have no effect on the BST functions).
Minimal assistance will be provided for this part of the assignment, especially if you cannot
demonstrate a fully implemented and thoroughly tested solution to part A.
Testing
It can be very time consuming to thoroughly test a program like this when all input is done
manually (imagine testing that your solution can manage 10000 customers). A common
method of testing code like this is to use input redirection (and possibly output redirection).
When using input redirection your code runs without modification, but all input comes from a
file instead of from the keyboard.
This facility is provided in Visual Studio through the project properties dialog. For example, to
redirect input from a file called“test.txt”, you would add:
<“$(ProjectDir)test.txt”
to Configuration Properties|Debugging|Command Arguments. This will be demonstrated in
tutorials.
At least one small input test file with sample output will be provided. It is recommended that
you construct larger files to fully test your program.
Assignment Submission
Assignments will be submitted via MyLO (an Assignment 1 dropbox will be created). You
should use the following procedure to prepare your submission:
Make sure that your project has been thoroughly tested using the School’s lab
computers
Choose“Clean Solution”from the“Build”menu in Visual Studio. This step is very
important as it ensures that the version that the marker runs will be the same as the
version that you believe the marker is running.
Quit Visual Studio and zip your entire project folder along with a completed
assignment cover sheet
Upload a copy of the zip file to the MyLO dropbox
History tells us that mistakes frequently happen when following this process, so you should
then:
Unzip the folder to a new location
Open the project and confirm that it still compiles and runs as expected
o If not, repeat the process from the start
KIT205 Data Structures and Algorithms: Assignment 1 – Data Structures
Synopsis of the task and its context
This is an individual assignment making up 10% of the overall unit assessment. The assessment criteria for this task are: - Select appropriate data structures to store problem-specific data
- Adapt generic data structures for use in a specific problem
- Implement generic list data structures and algorithms
- Implement generic tree data structures and algorithms
A significant and extremely important part of software development is thorough testing. Small programming errors may attract a large penalty if the error is something
that should have been picked up in testing! Please try to complete your program early to leave enough time for testing.
Match between learning outcomes and criteria for the task:
Unit learning outcomes
On successful completion of this unit you will be able to … Task criteria: - Transform a real-world problem into a simple abstract form that is suitable for efficient computation
- Implement common data structures and algorithms using a common programming language
- Analyse the theoretical and practical run time and space complexity of computer code in order to select algorithms for
specific tasks - Use common algorithm design strategies to develop new algorithms when there are no pre-existing solutions
- Create diagrams to reason and communicate about data structures and algorithms
1, 2
3, 4
–
–
–
Criteria HD (High Distinction) DN (Distinction) CR (Credit) PP (Pass) NN (Fail)
You have: You have: You have: You have: You have: - Select appropriate data
structures to store
problem-specific data
Weighting 10%
Data structures have been mapped
to problem data in a way that
promotes efficient time and memory
utilisation
Data structures have been mapped to problem data Working linked list and
BST code from tutorials,
but little attempt to match
data structures to problem
data - Adapt generic data
structures for use in a
specific problem
Weighting 15%
Correct adaption of linked list data
structure for storing customers,
programs or subscriptions - and –
Correct adaption of tree data
structure for storing customers,
programs or subscriptions
Correct adaption of linked list data structure for
storing customers, programs or subscriptions - or –
Correct adaption of tree data structure for
storing customers, programs or subscriptions
Partially correct adaption of linked list
data structure for storing customers,
programs or subscriptions - or –
Partially correct adaption of tree data
structure for storing customers,
programs or subscriptions
Correct code for input
loop, but little attempt to
adapt data structures for
this problem - Implement generic list
data structures and
algorithms
Weighting 25%
Linked list functions implemented
correctly, including freeing all
memory correctly (including on quit)
Linked list functions
implemented correctly,
without freeing all
memory
Implemented some linked list functions correctly for this
problem
Little attempt to get linked
list operations working - Implement generic tree
data structures and
algorithms
Weighting 50%
AVL functions implemented
correctly, including freeing all
memory correctly (including on quit)
Implemented some
AVL functions correctly
for this problem.
BST functions
implemented correctly,
including freeing all
memory correctly
(including on quit)
Implemented some BST functions
correctly for this problem.
Little attempt to get BST
operations working
WX:codehelp