题解 | #网购#

#include <stdio.h>

int main() {
    double val,ret = 0;
    int month,day,is_have_coupon=0;
    scanf("%lf %d %d %d",&val,&month,&day,&is_have_coupon);
    if(month==11&&day==11){
        ret=val*0.7-is_have_coupon*50.0;
        if(ret<0)
        ret=0;
    }
    else if(month==12&&day==12){
        ret=val*0.8-is_have_coupon*50.0;
        if(ret<0)
        ret=0;
    }
    else {
        ret=val;
    }
    printf("%.2lf",ret);
    return 0;
}