qsort function - trying to use a comparator

Question

I made a qsort function for a larger program. It is to sort by time. I have a class schedule I am working with and found a need to compare time with AM and PM. ie if A is chosen

Answer 1

Just add separate check for AM vs PM and make any AM time be less than PM time:

int sortFunction(const void *p, const void *q) {
  return
    (sched_record *) p)->am_pm < (sched_record *) q)->am_pm ?
      -1 :
    (sched_record *) p)->am_pm > (sched_record *) q)->am_pm ?
       1 :
       ((sched_record *) p)->start.hour -
               ((sched_record *) q)->start.hour;
}

presumably in your sched_record the am_pm field will hold 1 for am and 2 for pm, or something like that.

edit: turns out the OP doesn't have am_pm indicator in their structure and so must probably use 24 hour time representation, apparently with integers for hours and minutes:

int sortFunction(const void *p, const void *q) {
  return
    (sched_record *) p)->start.hour < (sched_record *) q)->start.hour ?
      -1 :
    (sched_record *) p)->start.hour > (sched_record *) q)->start.hour ?
       1 :
       ((sched_record *) p)->start.minutes -
               ((sched_record *) q)->start.minutes;
}