题解 | 网购

#include <stdio.h>

int main() {
   float num,price;
   scanf("%f",&num);
   int month,day,a;
   scanf("%d%d%d",&month,&day,&a);
   if(month==11&&day==11)
   {
    if(a==1)
     price=num*0.7-50;
     else
       price=num*0.7;
   }
      if(month==12&&day==12)
   {
    if(a==1)
     price=num*0.8-50;
     else
       price=num*0.8;
   }
  if(price<0)
  printf("0.00");
  else
   printf("%.2f",price);
    return 0;
}