输入字母后如何必需回车确认呢
程序代码：#include<stdio.h>
#define artichoke 1.25
#define beet 0.65
#define carrot 0.89
#define pound_5 3.50
#define pound_5_20 10.00
#define pound_20 8.00
double judge(double i);
double judge(double i)
{
while(1)
{
while(scanf("%lf",&i)!=1)
{
fflush(stdin);
printf("格式错误，重新输入\n");
}
if(i<0)
printf("磅数错误，重新输入\n");
else
break;
}
return i;
}
int main(void)
{
double amount,favorable,total_pound,artichoke_pound,beet_pound,carrot_pound,freight;
artichoke_pound=beet_pound=carrot_pound=0.0;
char ch;
printf("请选择您要下的订单,输入a为朝鲜蓟订单,b为甜菜订单,c为胡萝卜订单,q退出订单系统\n");
ch=getchar();
while(ch!='q')
{
switch(ch)
{
case 'a':printf("欢迎订购朝鲜蓟，请输入您要的磅数\n");
artichoke_pound=judge(artichoke_pound);
printf("请选择您要下的订单，按q退出订单系统并计算费用\n");
fflush(stdin);
ch=getchar();
break;
case 'b':printf("欢迎订购甜菜，请输入您要的磅数\n");
beet_pound=judge(beet_pound);
printf("请选择您要下的订单，按q退出订单系统并计算费用\n");
fflush(stdin);
ch=getchar();
break;
case 'c':printf("欢迎订购胡萝卜，请输入您要的磅数\n");
carrot_pound=judge(carrot_pound);
printf("请选择您要下的订单，按q退出订单系统并计算费用\n");
fflush(stdin);
ch=getchar();
break;
default:
printf("无此项订单，请重新选择\n");
fflush(stdin);
ch=getchar();
}
}
total_pound=artichoke_pound+beet_pound+carrot_pound;
favorable=(int)total_pound/100;
if(total_pound-20<=-15)
{
freight=pound_5;
amount=artichoke_pound*artichoke+beet_pound*beet+carrot_pound*carrot-favorable*0.05+freight;
}
else if(total_pound-20>-15&&total_pound-20<=0)
{
freight=pound_5_20;
amount=artichoke_pound*artichoke+beet_pound*beet+carrot_pound*carrot-favorable*0.05+freight;
}
else
{
freight=(int)total_pound/1*0.1+8.00;
amount=artichoke_pound*artichoke+beet_pound*beet+carrot_pound*carrot-favorable*0.05+freight;
}
printf("您订购了%.2lf磅朝鲜蓟,%.2lf磅甜菜,%.2lf磅胡萝卜,总计%.2lf磅。\n",artichoke_pound,beet_pound,carrot_pound,total_pound);
printf("您需要支付运输和装卸费用$ %.2lf,您可以获得$ %.2lf优惠,总费用为$ %.2lf\n",freight,favorable,amount);
return 0;
}
再输入a20的情况下，会把后面的数据提前录入，输入字母后如何必需回车确认呢
