#include <stdio.h>
float price(int dictance,int useTime)
{
   int startPrice = 13;
   float fuel = 1;
   float milePrice = 2.3;
   float totalPrice;
   while(useTime<5||useTime>=23)
   {
       if(useTime<0||useTime>24)
       {
           printf("%s\n","时间输入有误。");
           return 0;
           break;
       }
       else
       {
           milePrice*=1.2;
           break;
       }
   }
   if(distance<=3)
   {
       totalprice = startPrice+fuel;
   }
   else
   {
       totalPrice = startPrice+milePrice*(dictance-3)+fuel;
   }
   return totalPrice;
}

int main()
{
   int amTime = 9;
   int pmTime = 18;
   int distance = 12;
   printf("小明上午打车的费用是%f\n",price(distance,amTime));
   printf("小明下午打车的费用是%f\n",price(distance,pmTime));
   printf("小明打车的总费用是%f\n",price(distance,amTime)+price(distance,pmTime));
   return 0;
}

运行结果如下：

/249/5642/CD9l/hello.c: In function 'price':
/249/5642/CD9l/hello.c:22:8: error: 'distance' undeclared (first use in this function)
    if(distance<=3)
       ^
/249/5642/CD9l/hello.c:22:8: note: each undeclared identifier is reported only once for each function it appears in
/249/5642/CD9l/hello.c:24:9: error: 'totalprice' undeclared (first use in this function)
        totalprice = startPrice+fuel;