Poj Solution 2613

http://poj.org/problem?id=2613

/* @author: */
import java.util.Scanner;
public class Main{

 public static void main(String args[]){
  Scanner sc=new Scanner(System.in);  

  int a[]=new int[3],b[]=new int[3],c[]=new int[3],d[]=new int[3],p,q,r,s;
  int maxn;
  double sum;

    int i,flag;
    maxn=100000001;
    while(sc.hasNext())
    {
        p=sc.nextInt();
        q=sc.nextInt();
        r=sc.nextInt();
        s=sc.nextInt();

        a[0]=p;a[1]=s;a[2]=r-s;b[0]=r;b[1]=q;b[2]=p-q;
        for(i=0;i< 3;i++)c[i]=d[i]=2;
        sum=1;flag=1;
        while(flag!=0)
        {
            flag=0;
            for(i=0;i< 3;i++)
            {
                if(sum< maxn&&c[i]<=a[i])
                {
                    flag=1;
                    sum*=c[i]++;
                }    
                if(sum>0.00000001&&d[i]<=b[i])
                {
                    flag=1;
                    sum/=d[i]++;
                }    
            }    
        }    
        System.out.printf("%.5fn",sum);
    }    
   }
}