CS 2073 Lab 6: Functions
Chia-Tien Dan Lo
Department of Computer Science, UTSA
I Objectives
•Demonstrate your ability to write and call C functions
•Define and using C preprocessor files
II Hand-in Requirements
All laboratories will be submitted electronically through WebCT. Zip up your entire project folder to submit as the
source. (Right click on the laboratory folder and follow the SentTo link.)
III Details
In this assignment, you will be writing some C functions, using C include headers, and call them. Design a C file,
“utility.c”, that contains the following functions. The prototypes in the file are as follows.
/* The function quadratic calculates the solutions of the quadratic
equation based on the formula:
ax2+bx +c= 0
x1 = −b−√b2−4ac
2a
x2 = −b+√b2−4ac
2a
It return 0 if no real number solutions, 1 if one (repeated) solution, or
2 if two solutions are found. The solutions are stored in x1 and x2 using
call-by-reference technique. x1 will store the solution if 1 is returned.
Both x1 and x2 store solutions if 2 is returned. Otherwise, x1 and x2
are invalid. The following table lists some test cases:
a b c x1 x2 return value
---- ---- ---- ---- ---- ------------
1 -2 1 1 1 1
1 1 1 x x 0
1 -3 2 1 2 2
Note x in the table means don’t care.
*/
int quadratic(int a, int b, int c, double *x1, double *x2)
/* returns the factorial of number.
The function fact(5) should return 120. (1 * 2 * 3 * 4 * 5 = 120)
*/
double fact(int number)
/* Outputs all of the divisors for number including 1 and the number
The function print_all_divisor(24) outputs 1 2 3 4 6 8 12 24
1
