求助 ！！！！高手进

main()
{
int data1, data2; /*定义两个操作符*/
char op; /*定义运算符*/
printf("Please enter the expression:");
scanf("%d%c%d", &data1, &op, &data2); /*输入运算表达式*/
switch (op)
{
case '+': /*处理加法*/
printf("%d + %d = %d\n", data1, data2, data1 + data2);
break;
case '-': /*处理减法*/
printf("%d - %d = %d\n", data1, data2, data1 - data2);
break;
case '*': /*处理乘法*/
printf("%d * %d = %d\n", data1, data2, data1 * data2);
break;
case '/': /*处理除法*/
if (0 == data2)
printf("Division by zero!\n");
else
printf("%d/%d = %d\n", data1, data2, data1/data2);
break;
default:
printf("Unknown operator! \n");
}
}


原题是这个 1 2 两个问做出来老 求高手请教3 4问啊

麻烦进来个人吗