题解 | 简单计算器

#include <stdio.h>

int main() 
{
double a,b;
int d = 0;//计数

char s[2];

while(scanf("%lf%1s%lf",&a,s,&b)!=EOF)
{
    if(s[0]=='+')
    {
        printf("%.4lf+%.4lf=%.4lf\n",a,b,a+b);
        d++;
    }
    else if(s[0]=='*')
    {
        printf("%.4lf*%.4lf=%.4lf\n",a,b,a*b);
        d++;
    }
    else if(s[0]=='/')
    {
        if(b==0)
        {
            printf("Wrong!Division by zero!\n");
        }
        else 
        {
            printf("%.4lf/%.4lf=%.4lf\n",a,b,a/b);
        }
        d++;
    }
    else if(s[0]=='-')
    {
    printf("%.4lf-%.4lf=%.4lf\n",a,b,a-b);
    }

    else if(d==0)
    {
        printf("Invalid operation!\n");
    }

}

}