题解 | #简单计算器#

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