Question

I finished the programming of a class project, but I still need to get the running time. I tried clock() function, but it didn’t work.

int main()
{
  clock_t start_time=clock();
  (my codes)
  clock_t end_time=clock();
  printf("The running time is %f", end_time-start_time);
}

I guess this is the right way to use clock function, am I right? But I got nothing but 0.000000. Could someone tell me the right way? Thank you!

Answer 1

clock_t is not a float, but an integer type, most probably a long.

So you might use %ld to printf() it.

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Also clock() does not return seconds, but CPU ticks. So to get seconds the value returned by clock() shall be devided by the system constant CLOCKS_PER_SEC.