c - if 语句代码 - 使其更简单 - 需要建议

Question

我正在从《学习 C 编程:现代方法》一书中学习 C，我在必须计算关闭出发时间和到达时间的任务中遇到了一些麻烦。所以我在stackoverflow上发现了一个问题。

这个:If statement and expressions question advice (要完全理解我在说什么，请查看原始帖子)

这段代码让我很困扰，其中似乎有些不对劲。如果您运行此代码并尝试输入时间(例如 08:25)，它将显示关闭出发时间为 08:00，但该时间已经过去。

   #include <stdio.h>

    int main (int argc, const char * argv[]) {


    // Flight departure times since midnight
    // 8am, 9:45am, 11:19am, 12:47pm
    // 2pm, 3:45pm, 7pm, 7:45pm
         int a = 480, b = 585, c = 679, d = 767,
         e = 840, f = 945, g = 1140, h = 1185;

    // Flight arrival times for respective departure times.
          int a1 = 616, b1 = 712, c1 = 811, d1 = 900,
          e1 = 968, f1 = 1075, g1 = 1280, h1 = 1438;

          int hours, minutes, time, t, u;

    // Get the users time

          printf("Enter a 24 hour time (hh:mm): \n");
          scanf("%d:%d", &hours, &minutes);

          time = hours * 60 + minutes;

          printf("Closest departure time is ");

       if (time <= a)
          printf("8:00am");
             else
           if (time > a && time <= b) {
            t = time - a; 
            u = b - time;
            if (t < u) {
                printf("%.2d:%.2d", a / 60, a % 60);
                    if (a / 60 == 0)
                        printf("am");
                    else if (a / 60 < 12)
                        printf("am");
                    else if (a / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");
                printf(", arriving at %d:%.2d", a1 / 60, a1 % 60);
                    if (a1 / 60 == 0)
                        printf("am");
                    else if (a1 / 60 < 12)
                        printf("am");
                    else if (a1 / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");
            }
            else {
                    printf("%.2d:%.2d", b / 60, b % 60);
                    if (b / 60 == 0)
                        printf("am");
                    else if (b / 60 < 12)
                        printf("am");
                    else if (b / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");
                printf(", arriving at %d:%.2d", b1 / 60, b1 % 60);
                    if (b1 / 60 == 0)
                        printf("am");
                    else if (b1 / 60 < 12)
                        printf("am");
                    else if (b1 / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");
            }
}

如果代码看起来像这样，不是吗(这段代码短了 50%，并且没有任何不必要的计算):

         if (time_val < a)
    {
                    printf("%.2d:%.2d", a / 60, a % 60);
                    if (a / 60 == 0)
                        printf("am");
                    else if (a / 60 < 12)
                        printf("am");
                    else if (a / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");
                printf(", arriving at %d:%.2d", a1 / 60, a1 % 60);
                    if (a1 / 60 == 0)
                        printf("am");
                    else if (a1 / 60 < 12)
                        printf("am");
                    else if (a1 / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");

}
   else if (time_val < b)
              {
                    printf("%.2d:%.2d", b / 60, b % 60);
                    if (b / 60 == 0)
                        printf("am");
                    else if (b / 60 < 12)
                        printf("am");
                    else if (b / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");
                printf(", arriving at %d:%.2d", a2 / 60, a2 % 60);
                    if (a2 / 60 == 0)
                        printf("am");
                    else if (a2 / 60 < 12)
                        printf("am");
                    else if (a2 / 60 == 12)
                        printf("pm");
                    else
                        printf("pm");

你们能告诉我，我在这里遗漏了什么吗？

已添加让我具体说明一下最让我困惑的女巫部分

      if (time <= a)
          printf("8:00am");
             else
           if (time > a && time <= b) {
    //why in the hell this calculation and if condition(below) would be necessary? 
    //It messes up the whole program. try the previous script. 
    //(Don't worry about the time calculations, I made them way simpler, I just wanted to leave
    //the original script)
            t = time - a; 
            u = b - time;
            if (t < u) 

Answer 1

这段代码:

                if (b / 60 == 0)
                    printf("am");
                else if (b / 60 < 12)
                    printf("am");
                else if (b / 60 == 12)
                    printf("pm");
                else
                    printf("pm");

相当于:

                if (b / 60 < 12)
                    printf("am");
                else
                    printf("pm");