题解 | #网购#

#include <stdio.h>

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

主要是注意折后价小于50并且有优惠券的情况，这时候花费为0.00。