C语言计算器。请编写一个程序，实现一个简单的对整数进行加、减、乘、除、求余，输入的格式“操作数1 运算符op 操作数2”，最后输出表达式的值。若除数为0，则输出“Division by zero”；若运算符非法，则输出“Invalid operator!”

#include <stdio.h>

int main()
{
int num1, num2;
char op;

scanf("%d %c %d", &num1, &op, &num2);

switch(op)
{
case '+':
printf("%d", num1 + num2);
break;
case '-':
printf("%d", num1 - num2);
break;
case '*':
printf("%d", num1 * num2);
break;
case '/':
if(num2 == 0)
printf("Division by zero");
else
printf("%d", num1 / num2);
break;
case '%':
if(num2 == 0)
printf("Division by zero");
else
printf("%d", num1 % num2);
break;
default:
printf("Invalid operator!");
break;
}

return 0;
}