#include<stdio.h>
int main()
{
int num;
double price;
double discount;
double total;
printf("======================================\n");
total=0.0;
do
{
scanf("%d",&num);
if(num==0)
{电话计费系统
break;
}
printf("请输入商品价格:");
scanf("%lf",&price);
printf("请输入商品的折扣");
scanf("%lf",&discount);
total=num*price*discount;
printf("\n");
}while(num!=0);
printf("==========================================");
printf("你本次购物应付金额为:%lf",total);
return 0;
}