#include<stdio.h>

main()

{

float a,b;

char c;

printf("输入表达式如a+(* -  /)b:\n");

scanf("%f%c%f",&a,&c,&b);

switch(c)

{

case'+':printf("%f\n",a+b);break;

case'-':printf("%f\n",a-b);break;

case'*':printf("%f\n",a*b);break;

case'/':printf("%f\n",a/b);break;

}

 

return 0;

}