题解 | #网购#

#include <stdio.h>

int main() 
{
    double price;
    int month;
    int day;
    int paper;
    scanf("%lf %d %d %d", &price, &month, &day, &paper);
    if (month == 11 && day ==11)
    {
        price *= 0.7;
    }
    else if((month == 12 && day ==12))
    {
        price *= 0.8;
    }
    if(paper == 1)
    {
        price -= 50;
    }
    if (price < 0)
    {
        printf("0.00\n");
    }
   else
   printf("%.2lf", price);
    return 0;
}