Description
Question 1 [8 marks]
Write a function that interlaces a positive 4-digit int between 1000 and 9999 with another positive 5-digit
int between 10000 and 99999, and returns the result as a positive 9-digit int. Use this function header:
unsigned int interlace_ints(unsigned int firstNum, unsigned int secondNum)
For example:
interlace_ints(1000, 99999) should return 919090909
interlace_ints(2345, 11111) should return 121314151
interlace_ints(2468, 13579) should return 123456789
Only include the function definition in your answer and name the source file containing it as question1.c.
Do not use recursion in your answer.
Question 2 [8 marks]
Write a function that takes in 4 parameters: an int array, its size, an int as a target, and a char array of size
32; and puts a cstring in the format A+B to that char array, where A and B are the indexes of a pair of
elements in the int array that add up to the target value (note that A and B cannot be the same). If there
are multiple pairs, any pair will do. If no such pair exists, put the cstring that reads not_found. Use this
function header:
void findPair(int array[], unsigned int size, int target, char* result)
For example:
Assignment 1 CMPT 125 Intro. To Computing Science & Programming II Spring 2021
Page 2 of 4 © Victor Cheung, 2021
Given the array intArr1: {-1, 0, 2, 3, 4, 5, 6, 7} and the char array pair
findPair(intArr1, 8, -1, pair) should put the cstring 0+1 in pair
findPair(intArr1, 8, 5, pair) should put the cstring 0+6 in pair (1+5 and 2+3 are also valid)
findPair(intArr, 8, 25, pair) should put the cstring not_found in pair
You can assume there are at least 2 elements in the int array and the size is a valid number (not negative
and is the actual size of the array). You can also assume that the resulting pair will not exceed 31 characters.
As a hint, look up the sprintf function instead of printf. Only include the function definition in your answer
and name the source file containing it as question2.c. Do not use recursion in your answer.
Question 3 [8 marks]
Write a function that takes in the dimensions (rows and columns) of a 2D array of ints and the array itself,
and performs a row subtraction operation as indicated by 2 other parameters representing the row
numbers (indexes, start with 0, not 1). This function does not return anything as the change is within the
2D array. Use this function header:
void rowSubtraction(unsigned int rows, unsigned int columns,
int matrix[rows][columns], unsigned int row1, unsigned int row2)
For example:
Given the 3×4 2D array matrix1: {{1, 2, 3, 2}, {2, 3, 4, 3}, {1, 1, 1, 1}},
rowSubtraction(3, 4, matrix1, 0, 1) modifies matrix1 into {{-1, -1, -1, -1}, {2, 3, 4, 3}, {1, 1, 1, 1}}
rowSubtraction(3, 4, matrix1, 1, 2) further modifies matrix1 into {{-1, -1, -1, -1}, {1, 2, 3, 2}, {1, 1, 1, 1}}
rowSubtraction(3, 4, matrix1, 2, 3) does not cause any changes to matrix1 as there is no row indexed 3
You can assume rows and columns represent the dimensions of the array correctly and the dimensions
are either both positive (regular matrix) or both zero (empty matrix). However, any of row1 and row2 can
have values accessing beyond the number of the rows and if that happens the matrix remains unchanged.
Only include the function definition in your answer and name the source file containing it as question3.c.
Question 4 [12 marks]
Write a function that takes in a cstring (i.e., a character array that has a \0 character as the last element)
that represents a mathematics operation (+, -, or *), and returns the result as an int. Use this function
header:
int performMathOp(char* operation)
For example:
performMathOp(“12+345”) should return 357
performMathOp(“0-4”) should return -4
performMathOp(“13*13”) should return 169
Assignment 1 CMPT 125 Intro. To Computing Science & Programming II Spring 2021
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You can assume that the representation is valid (digits for the 2 numbers, one of the +/-/* between them)
and neither of them are negative, with no space between any of the numbers and the operator. Only
include the function definition in your answer and name the source file containing it as question4.c.
Coding Style [4 marks]
Your program should be correctly indented, have clear variable names and enough white space and
comments to make it easy to read. Named constants should be used where appropriate. Each line of code
should not exceed 80 characters. White space should be used in a consistent manner.
To help you to get into the habit of good coding style, we will read your code and marks will be deducted
if your code is not styled properly.
Using the Makefile and Other Supplied Files
The Makefile provided in this assignment is used by a command in the CSIL machines called “make” to
quickly compile your code. It is especially useful if you have multiple source files. To use it, type the
following command in the prompt (make sure you are in the directory with all the files of Assignment 1):
$ make test1
The example above illustrates how Question 1 is compiled into an executable called “test1” when using
the Makefile. Replace the “test1” with “test2”, “test3”, …etc. for other questions. You can then run the
executable by typing “./test1” to test your code for Question 1. If you make changes to your code, use the
make command again. You can also use “make all” if you want to compile all 4 at once.
The test files (test1.c, test2.c, …etc.) are provided in this assignment for you to test your code. Each
typically contains a main function along with other tester functions and/or calls. You can modify them to
further test your code, but do not submit these test files because we will be using our test files that are
similar but not identical to grade your assignment. This makes sure that your code is not written to
produce hard-coded output.
The header files (question1.h, question2.h, …etc.) are there to make the compilation work. Ignore them
and do not modify them. You also do not have to submit them.
Submission
Submit only the 4 source files indicated above (question1.c, question2.c, question3.c, question4.c) by
compressing them into a zip file (do not put them into a folder and zip them) and upload it to Canvas by
11:59p Jan 29. Name the zip file in this format: __Assignment1.zip.
For example, John_Smith_012345678_Assignment1.zip
Assignment late penalty: 10% per calendar day (each 0 to 24 hour period past due), max 2 days late.
Academic Honesty
It is expected that within this course, the highest standards of academic integrity will be maintained, in
keeping with SFU’s Policy S10.01, “Code of Academic Integrity and Good Conduct.” In this class,
collaboration is encouraged for in-class exercises and the team components of the assignments, as well
as task preparation for group discussions. However, individual work should be completed by the person
who submits it. Any work that is independent work of the submitter should be clearly cited to make its
Assignment 1 CMPT 125 Intro. To Computing Science & Programming II Spring 2021
Page 4 of 4 © Victor Cheung, 2021
source clear. All referenced work in reports and presentations must be appropriately cited, to include
websites, as well as figures and graphs in presentations. If there are any questions whatsoever, feel free
to contact the course instructor about any possible grey areas.
Some examples of unacceptable behavior:
• Handing in assignments/exercises that are not 100% your own work (in design, implementation,
wording, etc.), without a clear/visible citation of the source.
• Using another student’s work as a template or reference for completing your own work.
• Using any unpermitted resources during an exam.
• Looking at, or attempting to look at, another student’s answer during an exam.
• Submitting work that has been submitted before, for any course at any institution.
All instances of academic dishonesty will be dealt with severely and according to SFU policy. This means
that Student Services will be notified, and they will record the dishonesty in the student’s file. Students
are strongly encouraged to review SFU’s Code of Academic Integrity and Good Conduct (S10.01) available
online at: http://www.sfu.ca/policies/gazette/student/s10-01.html.
