E1 – Fundamentals Please refer to announcements for details about this exam. Make sure you fill the information below to avoid not being graded properly; Last Name Thalheimer First Name Kristoffer Student ID # Thalheimer Here is the grading matrix where the TA will leave feedback. If you scored 100%, you will most likely not see any feedback ( Question # points Feedback Max Scored 1 Tracing 3 2 Testing 2 3 Refactoring 2 4 Debugging 3 Question #1 – Tracing Programs We are going to trace the following program, i.e. simulate in your head how it would execute on a computer. To help you, a trace table is provided for you to fill. For each “execution step” of the program, write down in the table the line being executed along with the value of each variable which was modified. Please note that we omitted the usual main function definition and other #include statements. We assume the following fragment to be inside a main function. Program to Trace 1 int something = 5; 2 int data = 42; 3 int n = 0; 4 5 for( n = 0 ; data > 0 ; n++){ 6 data -= something; 7 } 8 9 if( data < 0) n--; Trace Table to Fill Feel free to add / remove rows if necessary Step # Line # Variables Values Remarks something data n 1 2 3 … Question #2 – Testing Programs You are going to write tests for the following program fragment which we assume to be inside a main function. Its requirements are to · Prompt the user for two int numbers X and Y · If Y is zero the program should display “Error #1” then exit. · Otherwise, if any of the two input value is less or equal to zero, it should display “Error #2” then exit. · Otherwise, it should display how many times Y goes into X. This is the equivalent of the integer division of X by Y. Your objective is to write tests which will guarantee · The program conforms to the requirements · All possible execution paths have been tested · Your program does not feature any errors Program to Test 1 int div = 0; 2 int data = 0; 3 int n = 0; 4 printf("Enter positive int to divide: "); 5 scanf("%d", &data); 6 7 printf("Enter positive int to divide it by: "); 8 scanf("%d", &div); 9 10 if(div == 0){ 11 printf("Error #1\n"); 12 exit(EXIT_FAILURE); 13 } 14 15 if((data <= 0) || (div <= 0)){ 16 printf("Error #2\n"); 17 exit(EXIT_FAILURE); 18 } 19 20 for( n = 0 ; data > 0 ; n++){ 21 data -= div; 22 } 23 24 if( data < 0) n--; 25 26 printf("Ouput value is %d\n", n); Tests Table to Fill Feel free to add / remove rows if necessary Test # Inputs’ Values Expected Results Explanations; What did you use this test for? Why is it not redundant with others? div data n Error 1 2 3 … Question #3 – Refactoring Programs Refactor the following code to improve it in terms of readability, documentation, redundancy. Regarding redundancy, we really don’t like having twice the same printf/scanf but we don’t want a solution where the ...

1. E1 – Fundamentals
Please refer to announcements for details about this exam. Make
sure you fill the information below to avoid not being graded
properly;
Last Name
Thalheimer
First Name
Kristoffer
Student ID #
Thalheimer
Here is the grading matrix where the TA will leave feedback. If
you scored 100%, you will most likely not see any feedback (
Question
# points
Feedback
Max
Scored
1
Tracing
3
2
Testing
2
3

2. Refactoring
2
4
Debugging
3
Question #1 – Tracing Programs
We are going to trace the following program, i.e. simulate in
your head how it would execute on a computer. To help you, a
trace table is provided for you to fill.
For each “execution step” of the program, write down in the
table the line being executed along with the value of each
variable which was modified.
Please note that we omitted the usual main function definition
and other #include statements. We assume the following
fragment to be inside a main function.
Program to Trace
1
int something = 5;
2
int data = 42;
3
int n = 0;
4
5
for( n = 0 ; data > 0 ; n++){

3. 6
data -= something;
7
}
8
9
if( data < 0) n--;
Trace Table to Fill
Feel free to add / remove rows if necessary
Step #
Line #
Variables Values
Remarks
something
data
n
1
2

4. 3
…
Question #2 – Testing Programs
You are going to write tests for the following program fragment
which we assume to be inside a main function. Its requirements
are to
· Prompt the user for two int numbers X and Y
· If Y is zero the program should display “Error #1” then exit.
· Otherwise, if any of the two input value is less or equal to
zero, it should display “Error #2” then exit.
· Otherwise, it should display how many times Y goes into X.
This is the equivalent of the integer division of X by Y.
Your objective is to write tests which will guarantee
· The program conforms to the requirements
· All possible execution paths have been tested
· Your program does not feature any errors
Program to Test
1

5. int div = 0;
2
int data = 0;
3
int n = 0;
4
printf("Enter positive int to divide: ");
5
scanf("%d", &data);
6
7
printf("Enter positive int to divide it by: ");
8
scanf("%d", &div);
9
10
if(div == 0){
11
printf("Error #1n");
12

6. exit(EXIT_FAILURE);
13
}
14
15
if((data <= 0) || (div <= 0)){
16
printf("Error #2n");
17
exit(EXIT_FAILURE);
18
}
19
20
for( n = 0 ; data > 0 ; n++){
21
data -= div;
22
}
23

7. 24
if( data < 0) n--;
25
26
printf("Ouput value is %dn", n);
Tests Table to Fill
Feel free to add / remove rows if necessary
Test #
Inputs’ Values
Expected Results
Explanations;
What did you use this test for?
Why is it not redundant with others?
div
data
n
Error
1
2
3

8. …
Question #3 – Refactoring Programs
Refactor the following code to improve it in terms of
readability, documentation, redundancy. Regarding redundancy,
we really don’t like having twice the same printf/scanf but we
don’t want a solution where the loop’s condition would be
repeated twice either.
You will provide your version in the “Your Modified Version”
subsection which is already pre-filled with the original. Then,
for each thing you modified, use the table in the “Summary”
subsection to summarize what you did & why you did it.
Program to Refactor
int grade = 0, total = 0, number = 0;
printf("Grade Average Programn");
printf("Enter grade outside of [0..100] to stopn");
printf("Enter a grade between 0 and 100 inclusive: ");
scanf("%d", &grade);
while((grade >0) && (grade <=100)){
total += grade; number += 1;

9. printf("Enter a grade between 0 and 100 inclusive: ");
scanf("%d", &grade);
}
Your Improved Version
int grade = 0, total = 0, number = 0;
printf("Grade Average Programn");
printf("Enter grade outside of [0..100] to stopn");
printf("Enter a grade between 0 and 100 inclusive: ");
scanf("%d", &grade);
while((grade >0) && (grade <=100)){
total += grade; number += 1;
printf("Enter a grade between 0 and 100 inclusive: ");
scanf("%d", &grade);
}
Summary of Improvements
Feel free to add rows to, or remove rows from, this table as
needed;
What did you modify
How did you modify it?
Why did you modify it?

10. Question #4 – Debugging Programs
The following program has build-time errors – i.e. syntax,
linker – along with runtime errors – i.e. logic of the program,
crashes. Some statements might also be simply useless.
We need you to list all of these in the table below along with
how you would fix them.Program to Debug
1
#include "stdio.c"
2
#include "stdlib.c"
3
4
int main(){
5
int mystery = 5;
6
int tmp = 0;
7
double data = 0.0;

11. 8
9
do{
10
prinf("Enter a floating point value: ");
11
scanf("%d", data);
12
13
tmp = (int)data;
14
if( tmp % 2)
15
prinf("The int part of %d", data);
16
prinf(" is an even numbern");
17
else

12. 18
prinf("The int part of %d", data);
19
prinf(" is an odd numbern");
20
21
prinf("Enter 1.0 to enter another value:");
22
scanf("%d", data);
23
}while( data = 1.0 )
24 }
25
Bugs Table
Identify each bug you find & provide the lines # where it
happens. In addition, explain what the problem was, then how
you fixed it. If the same bug appears at different line, just enter
it one time in the table but specify all the lines where it
happens.

13. Bug #
Lines #
Problem you identified
How you fixed it
Your Fixed Version
Apply all the fixes you listed in the table to the code below to
make it your fixed version. Please note that if a bug is fixed
below but not in the table, or the other way around, you won’t
get credit for it. You need to have both the bug and its
explanations in the table and have it fixed below.
#include "stdio.c"
#include "stdlib.c"
int main(){
int mystery = 5;

14. int tmp = 0;
double data = 0.0;
do{
prinf("Enter a floating point value: ");
scanf("%d", data);
tmp = (int)data;
if( tmp % 2)
prinf("The int part of %d", data);
prinf(" is an even numbern");

15. else
prinf("The int part of %d", data);
prinf(" is an odd numbern");
prinf("Enter 1.0 to enter another value:");
scanf("%d", data);
}while( data = 1.0 )
}