题解 | #简单计算器#

#include <stdio.h>
int main()
{
    double a,c;
    char b;
    while (scanf("%lf%c%lf", &a,&b,&c) != EOF)
    {
        double n;
        if (b != 43 && b != 45 && b != 42 && b != 47)
        {
            printf("Invalid operation!\n");
        }
        else if (b == '+')
        {
            n = a + c;
            printf("%.4f%c%.4f=%.4f\n",a,b,c,n);
        }
        else if (b == '-')
        {
            n = a - c;
            printf("%.4f%c%.4f=%.4f\n",a,b,c,n);
        }
        else if (b == '*')
        {
            n = a * c;
            printf("%.4f%c%.4f=%.4f\n",a,b,c,n);
        }
        else
        {
            if (c == 0.0)
            {
                printf("Wrong!Division by zero!\n");
            }
            else
            {
                n = a / c;
                printf("%.4f%c%.4f=%.4f",a,b,c,n);
            }
        }
    }
    return 0;
}