题解 | 网购

#include <stdio.h>

int main() {
    float price = 0;
    int month = 0;
    int date = 0;
    int num = -1;
    while ((month != 11 && date != 11)&&
    (month != 12 && date != 12)&&
    (num != 0 || num != 1)
    ) {
        scanf("%f %d %d %d",&price, &month, &date, &num);
    }
    if (month == 11) {
        if (num) {
            price *=  0.7;
            price -= 50;
            if (price > 0) {
                printf("%.2f",price);
            }
            else {
                printf("0.00");
            }
        }
        else {
            price *= 0.7;
            if (price > 0) {
                printf("%.2f",price);
            }
            else {
                printf("0.00");
            }
            
        }
    }
    else {
        if (num) {
            price *=  0.8;
            price -= 50;
            if (price > 0) {
                printf("%.2f",price);
            }
            else {
                printf("0.00");
            }
            
        }
        else {
            price *= 0.8;
            if (price > 0) {
                printf("%.2f",price);
            }
            else {
                printf("0.00");
            }
        }
    }

    return 0;
}