调用函数-运算器

#include <stdio.h>

double calculator(double a, double b, char oper)
{
    if (oper == '+')
    {
        return a+b;
    }
    else if (oper == '-')
    {
        return a-b;
    }
    else if (oper == '*')
    {
        return a*b;
    }
    else if (oper == '/')
    {
        if (b == 0)
        {
            printf("除数不能为零\n");
        }
        return a/b;
    }
    else
    {
        printf("bad number\n");
    }
    return 0;
}
int main()
{
    double a, b;
    char oper;
    scanf("%lf%c%lf", &a, &oper, &b);
    printf("%.1lf\n", calculator(a, b, oper));
    return 0;
}