一个适合新手的训练C题

#include<stdio.h>

#define A 19
#define B 17
#define C 12
int main(){
    int a,b,c;
    double sum = 0;
    scanf("A%dB%dC%d",&a,&b,&c);
    if(a>1){
        sum+=a*A*(0.95);
    }else{
        sum+=a*A;
    }
    if(b>1){
        sum+=b*B*(0.95);
    }else{
        sum+=b*B;
    }
    if(c>1){
        sum+=c*C*(0.59);
    }else{
        sum+=c*C;
    }
    if(sum>50)sum-=4;
    int t=a+b+c;
    int ex=t/3*6;    
    if(t%3)ex+=6;

    printf("Food prices:%.2f\n",sum);
    printf("Express fee:%d\n",ex);
    printf("Total:%.2f\n",sum+ex);



    return 0;
}