提交错地方了，提交到coding上了
#include<stdio.h>
main()
{
float a,b;
char chr;
scanf("%f%c%f",&a,&chr,&b);
switch(chr)
{
case'+':printf("%f+%f=%f ",a,b,a+b);break;
case'-':printf("%f-%f=%f ",a,b,a-b);break;
case'*':printf("%f*%f=%f ",a,b,a*b);break;
case'/':printf("%f/%f=%f ",a,b,a/b);
}
}