题解 | #网购#

#include<stdio.h>

int main()
{
    float price=0,zp=0;
    int month=0,day=0,quan=0;
    scanf("%f %d %d %d",&price,&month,&day,&quan);
    if(month==11&&day==11)
        zp=price*0.7;
    else if(month==12&&day==12)
        zp=price*0.8;
    else
        zp=price;
    if(quan)
        zp-=50;
    if(zp<0)//保证不会出现负数
        zp=0;
    printf("%.2f",zp);
    return 0;
}