题解 | #网购#

#include <stdio.h>

int main() {
    double price = 0, cost = 0;
    int month = 0, date = 0, discount = 0;
    scanf("%lf %d %d %d", &price, &month, &date, &discount);
    if (month == 11 && date == 11) {
        cost = 0.7 * price;
        if (discount == 1)
            cost -= 50;
    }
    if (month == 12 && date == 12) {
        cost = 0.8 * price;
        if (discount == 1)
            cost -= 50;
    }
    if((int)(cost)<0)
    cost = 0;
    printf("%.2lf",cost);
}