#include<stdio.h>
void main()
{
float a, b;
char c;
printf("请输入a(+-*/)b\n");
scanf("%f%c%f",&a,&c,&b);
switch (c)
{
case '+': printf("a+b=%f", a + b); break;
case '-': printf("a-b=%f", a-b); break;
case '*': printf("a*b=%f", a*b); break;
case '/': printf("a+b=%f", a/b); break;
}
system("pause");
}