题解 | #简单计算器#

#include <stdio.h>
double add(double x, double y)
{
    return (x+y);
}
double sub(double x, double y)
{
    return (x-y);
}
double mul(double x, double y)
{
    return (x*y);
}
double div(double x, double y)
{
    return (x/y);
}
int main()
{
    double x = 0;
    double y = 0;
    char c = 0;
    scanf("%lf%c%lf", &x, &c, &y);
    double ret = 0;
    if(c == '+')
    {
        ret = add(x, y);
    }
    else if(c == '-')
    {
        ret = sub(x, y);
    }
    else if(c == '*')
    {
        ret = mul(x, y);
    }
    else if(c == '/')
    {
        ret = div(x, y);
        if(y == 0)
        {
            printf("Wrong!Division by zero!\n");
            return 0;
        }
    }
    else {
    printf("Invalid operation!\n");
    return 0;
    }
    printf("%.4lf%c%.4lf=%.4lf", x, c, y, ret);
    return 0;
}