difference_between_two_time_periods_v1.c

/*

    difference_between_two_time_periods_v1.c

    https://www.programiz.com/c-programming/examples/time-structure


    You can find all my C programs at Dragan Milicev's pastebin:

    https://pastebin.com/u/dmilicev

*/

#include <stdio.h>

struct TIME
{
   int hours;
   int minutes;
   int seconds;
};

// Computes difference between time periods
void differenceBetweenTimePeriod(struct TIME start,
                                 struct TIME stop,
                                 struct TIME *diff )
{
    while (stop.seconds > start.seconds)
    {
      --start.minutes;
      start.seconds += 60;
    }

    diff->seconds = start.seconds - stop.seconds;

    while (stop.minutes > start.minutes)
    {
      --start.hours;
      start.minutes += 60;
    }

    diff->minutes = start.minutes - stop.minutes;
    diff->hours = start.hours - stop.hours;
}


int main(void)
{
    struct TIME startTime, stopTime, diff;

/*
    printf("\n Enter the start time. \n");
    printf("Enter hours, minutes and seconds: ");
    scanf("%d %d %d", &startTime.hours,
         &startTime.minutes,
         &startTime.seconds);

    printf("\n Enter the stop time. \n");
    printf("Enter hours, minutes and seconds: ");
    scanf("%d %d %d", &stopTime.hours,
         &stopTime.minutes,
         &stopTime.seconds);
*/

    startTime.hours   = 12;
    startTime.minutes = 34;
    startTime.seconds = 55;

    stopTime.hours   =  8;
    stopTime.minutes = 12;
    stopTime.seconds = 15;

    // Difference between start and stop time
    differenceBetweenTimePeriod(startTime, stopTime, &diff);

    printf("\nTime Difference: %d:%d:%d - ",
            startTime.hours,
            startTime.minutes,
            startTime.seconds);

    printf("%d:%d:%d ",
            stopTime.hours,
            stopTime.minutes,
            stopTime.seconds);

    printf("= %d:%d:%d \n",
            diff.hours,
            diff.minutes,
            diff.seconds);


    return 0;

} // main()