#include "stdio.h"
void main()
{float a,b;
char mark;
printf("请输入两个运算量:\n");
scanf("%f%f",&a,&b);
printf("请输入运算符:\n");
scanf("%c",&mark);
switch(mark){
case '+':printf("结果为:%f\n",a+b);break;
case '-':printf("结果为:%f\n",a-b);break;
case '*':printf("结果为:%f\n",a*b);break;
case '/':printf("结果为:%f\n",a/b);break;}
}