#includemain(){ float sprice=0,sumprice=0; int num=0; printf("输入商品单价:\n"); scanf("%f",&sprice); flushall(); printf("输入商品数量:\n"); scanf("%d",&num); flushall(); sumprice=sprice*num; switch((int)(sprice)/200) { case 0:break; case 1:sumprice*=0.98;break; case 2:sumprice*=0.95;break; case 3: