Compare execution time in C language

[Vagrant]

Homework Statement

I want to compare the execution times for DDA and Bresenham's Line algorithm using a C program. I used the clock_t command; I'm getting the execution time for Bresenham’s algorithm as 0.164835 but 0 for DDA.

3. The Attempt at a Solution

clock_t start,end;
start=clock();
Bresenham's line algorithm code
end=clock();
printf("time=%f\n",(end-start)/CLK_TCK);

start=clock();
DDA line algorithm code
end=clock();
printf("time=%f\n",(end-start)/CLK_TCK);

Also I'm getting t=0.164835 for both codes separately. Whereas DDA line algorithm should take more time. What is it that I’m doing wrong?

 

[Mark44]

Your times aren't granular enough for what you're trying to measure. The basic unit of the clock_t type is seconds, which is way too large for measuring operations that are happening at clock rates in the gigahertz range.