經典收藏（時差計算）

#include <stdio.h>

int main()
{
int hour1, minute1;
int hour2, minute2;

scanf("%d %d", &hour1, &minute1);
scanf("%d %d", &hour2, &minute2);

int ih = hour2 - hour1;
int im = minute2 - minute1;
if ( im <0 ) {
im = 60 + im;
ih --;
}

printf(“時間差是%d小時%d分。\n”, ih, im);

return 0;
}