习题1

#include<stdio.h>
int main(void)
{
    double num1,num2;
    char op;

    printf("Type in an expression:");
    scanf("%lf%c%lf",&num1,&op,&num2);

    if(op=='+')
        printf("=%.2f\n",num1+num2);
    else if(op=='-')
        printf("=%.2f\n",num1-num2);
    else if(op=='*')
        printf("=%.2f\n",num1*num2);
    else if(op=='/')
        printf("=%.2f\n",num1/num2);
    else
        printf("Unknow operator\n");

    return 0;
}