#include<stdio.h>

float calculate(float a,float b,float d,char c)

{

switch(c)

{

case "+":d=a+b;break;

case "-":d=a-b;break;

case "*":d=a*b;break;

case "/":d=a/b;break;

default :putchar("\a"); //若運算子號出現錯誤，則機器以發出聲音報錯，注意，單撇號不要丟了

}

return d;

}

int main()

{

float a,b,d,z;

char c;

printf("what dou you want to calculate\n");

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

z=calculate(a,b,d,c);

printf("%f%c%f=%f\n",a,c,b,z);

return 0;

}