HDU1170 Balloon Comes!

Balloon Comes!
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 19874    Accepted Submission(s): 7486
Problem Description
The contest starts now! How excited it is to see balloons floating around. You, one of the best programmers in HDU, can get a very beautiful balloon if only you have solved the very very very... easy problem.
Give you an operator (+,-,*,/--denoting addition, subtraction, multiplication, division respectively) and two positive integers, your task is to output the result.
Is it very easy?
Come on, guy! PLMM will send you a beautiful Balloon right now!
Good Luck!
 
Input
Input contains multiple test cases. The first line of the input is a single integer T (0 
Output
For each case, print the operation result. The result should be rounded to 2 decimal places If and only if it is not an integer.
 
Sample Input

   
   
   
   

    
    
    
    4
+ 1 2
- 1 2
* 1 2
/ 1 2
   
   
   
   

 
Sample Output

   
   
   
   

    
    
    
    3
-1
2
0.50
   
   
   
   

 
Author
lcy
water

#include <stdio.h>

void f(char ch, int a, int b)
{
    if(ch == '+') printf("%d
", a + b);
    else if(ch == '-') printf("%d
", a - b);
    else printf("%d
", a * b);
}

int main()
{
    int a, b, t;
    char str[2];
    scanf("%d", &t);
    while(t--){
        scanf("%s%d%d", str, &a, &b);
        if(str[0] != '/') f(str[0], a, b);
        else if(a % b == 0) printf("%d
", a / b);
        else printf("%.2lf
", (double)a / b);
    }
    return 0;
}