所以我正在编写一个收银机程序。我已经完成了大部分工作。我的程序快完成了。但是我有一个问题。如果用户想去外卖，这个程序要求用户选择产品并计算最后的总金额。但是当用户必须输入现金支付时，我遇到了一个问题。如果用户提供的现金超过用户选择购买的产品总金额，它会计算并退回用户找零，但如果现金用户给定的数量少于用户选择的产品总量，它应该显示“给定的数量不足。添加更多”。但它以负数形式显示整数值。它以负数形式显示变化。我有给出了底部的输出示例。请帮助我。它太令人沮丧了。'<' 运算符似乎不起作用。！=，==，> 工作正常。谢谢！
#include <stdio.h>
#include<conio.h>
#include<stdlib.h>
int main()
{
int a=8,b=10,c=20,d=50,e=30,x,subtotal1=0,subtotal2=0,subtotal3=0,subtotal4=0,subtotal5=0,shopping=1,cash;
int total=subtotal1+subtotal2+subtotal3+subtotal4+subtotal5;
char choice,code,choice2;
printf(" WELCOME TO KFC! \n");
printf("Here are our sample list of products you might be interested in.\n\n");
while(shopping)
{
printf("\nChoose your product Enter product code i.e:A,C etc\n\n");
printf("[A]\n");
printf("[B]\n");
printf("[C]\n");
printf("[D]\n");
printf("[E]\n");
printf("[Q] for Quitting\n\n");
code=getch();
if(code=='q' || code=='Q')exit(0);
if(code=='a' || code=='A')
{
printf("You have chosen 'A' and price is 8$\n\n");
printf("Enter Quantity:\n\n");
scanf("%d",&x);
subtotal1=a*x;
printf("Subtotal price is %d\n\n",subtotal1);
}
if(code=='b' || code=='B')
{
printf("You have chosen 'B' and price is 10$\n");
printf("Enter Quantity:\n");
scanf("%d",&x);
subtotal2=b*x;
printf("Subtotal price is %d\n",subtotal2);
}
if(code=='c' || code=='C')
{
printf("You have chosen 'C' and price is 20$\n");
printf("Enter Quantity:\n");
scanf("%d",&x);
subtotal3=c*x;
printf("Subtotal price is %d\n",subtotal3);
}
if(code=='d' || code=='D')
{
printf("You have chosen 'D' and price is 50$\n");
printf("Enter Quantity:\n");
scanf("%d",&x);
subtotal4=d*x;
printf("Subtotal price is %d\n",subtotal4);
}
if(code=='E' || code=='e')
{
printf("You have chosen 'E' and price is 30$\n");
printf("Enter Quantity:\n");
scanf("%d",&x);
subtotal5=e*x;
printf("Subtotal price is %d\n",subtotal5);
}
printf("Do you want to shop more?\n");
choice=getch();
if(choice=='y' || choice=='Y')shopping=1;
else if(choice=='n' || choice=='N')
{
total=subtotal1+subtotal2+subtotal3+subtotal4+subtotal5;
printf("Do you want to add them to takeout?\n\n");
choice2=getch();
if(choice2=='y' || choice2=='Y')
{
printf("Enter cash:\n");
scanf("%d",&cash);
total=subtotal1+subtotal2+subtotal3+subtotal4+subtotal5;
if(total < ("%d",&cash))
{
printf("You have given %d\n",cash);
printf("Your change is %d\n",cash-total);
}
else printf("Insufficient amount given.Add more.\n");
shopping=0;
}
else shopping=1;
}
}
}
WELCOME TO KFC!
Here are our sample list of products you might be interested in.
Choose your product Enter product code i.e:A,C etc
[A]
[B]
[C]
[D]
[E]
[Q] for Quitting
You have chosen 'A' and price is 8$
Enter Quantity:
12
Subtotal price is 96
Do you want to shop more?
Do you want to add them to takeout?
Enter cash:
90
You have given 90
Your change is -6
但它应该显示
“给定的数量不足。添加更多”
它没有那样做。为什么？