计算机加减乘除运算switch

#include<stdio.h>
main()
{
    float a,b,c;
    char x;
    printf("please input computing fomula\n");
    scanf("%f%c%f",&a,&x,&b);
    switch(x)
    {
    case(‘+‘):c=a+b;break;
    case(‘-‘):c=a-b;break;
    case(‘*‘):c=a*b;break;
    case(‘/‘):c=a/b;break;
    }
    printf("c=%d",c);
}
因此得到：99*88
please input the number figures:8712