C / C++ / MFC

#include <stdio.h>
#include <string.h>

typedef struct
{
	char name[100];
	int goals;

}match;

match check();

int main()
{
	int log;
	match team;
	
	scanf("%d", &log);

	printf("Enter goals:\n");
	scanf("%d", team.goals);
	
	fflush(stdin);
    team = check();
	printf("Name: %s\t\tGoals: %d\n", team.name, team.goals);

	return 0;
}

match check()
{
	int c;
	match temp;

	gets(temp.name);
	if((c=temp.name[0])==EOF && c == '\n')
	{
		printf("Invalid entry!");
		check(temp);
	}

	return(temp);
}

<pre>#include <stdio.h>

struct TIME
{
  int seconds;
  int minutes;
  int hours;
};
void differenceBetweenTimePeriod(struct TIME t1, struct TIME t2, struct TIME *diff);

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

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

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

    // Calculate the difference between the start and stop time period.
    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;
}

//not able to understand the logic.
void differenceBetweenTimePeriod(struct TIME start, struct TIME stop, struct TIME *diff)
{
    //how does this logic works??.
    if(stop.seconds > start.seconds){
        --start.minutes;
        start.seconds += 60;
    }

    diff->seconds = start.seconds - stop.seconds;
    if(stop.minutes > start.minutes){
        --start.hours;
        start.minutes += 60;
    }

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