exercise2.c

北大青鸟软件工程师ppt的学生用书源代码

#include <stdio.h>
void main ()
{
  /*用 ch 存储顾客是否是会员的信息
   *用 cost1、cost2 和 cost3 三个单精度浮点型变量存储购买商品的费用 */
  char ch;
  float cost1, cost2, cost3;
  float total_cost;
  double discount, pay;
  printf("\n 是否是会员?(y/n)");
  fflush(stdin);
  scanf("%c",&ch);
  printf("\n 输入购买第一件商品的费用：");
  scanf("%f", &cost1);
  printf("\n 输入购买第二件商品的费用：");
  scanf("%f", &cost2);
  printf("\n 输入购买第三件商品的费用：");
  scanf("%f", &cost3);
  
  total_cost = cost1 + cost2 + cost3;
  discount = 0;
  
  if((ch=='y') || (total_cost>=100))
  {
	  discount=total_cost*0.1;
  }
  if((ch=='y') && (total_cost >= 100))
  {
	  discount = total_cost * 0.2;
  }

  pay = total_cost - discount;
  printf("\n 购物总额 = %1.2f 元\n ", total_cost);
  printf("\n 折扣金额 = %1.2f 元\n ", discount);
  printf("\n 应付总额 = %1.2f 元\n ", pay);
}