自己寫的程式碼

思路：將開始和結束時間先轉成統一的分鐘，然後進行整除、取模。

 1 #include <stdio.h>
 2 int main(void)
 3 {
 4     int begin, end, sum1, sum2;
 5     int hour1, min1, hour2, min2, hour, min;
 6     scanf("%d %d", &begin, &end);
 7 
 8     hour1 = (begin / 100) * 60;          /*時轉換成分鐘*/
 9     min1 = begin % 100;
10
 
     sum1 = hour1 + min1;
11     hour2 = (end / 100) * 60;
12     min2 = end % 100;
13     sum2 = hour2 + min2;
14 
15     hour = (sum2 - sum1) / 60;
16     min = (sum2 - sum1) % 60;
17 
18     printf("%02d:%02d", hour, min);     /* 輸出時需兩位，不足補零 */
19 
20     return 0;
21 }

參考：簡化

#include <stdio.h>
int main(void
 
)
{
    int hh, mm;
    int a1, a2;
    scanf("%d %d", &a1, &a2);
    hh = a2/100 - a1/100;       /*小時*/
    mm = a2%100 - a1%100;       /*分鐘*/

    if ( mm<0 ){
        mm+=60;
        hh--;
    }
    printf("%02d:%02d", hh, mm);

    return 0;
}