Poj Solution 1564

http://poj.org/problem?id=1564

/* @author: */
import java.util.Scanner;
public class Main{
  static int sum,n;
  static int arr[]=new int[20];
  static int j,FLAG;
  static boolean used[]=new boolean[20];

  static void f(int now,int total)
  {
   int i;
   if(total==sum)
   {
     FLAG=1;
     for(i=0;i< n;i++)
     if(used[i])
     {
    System.out.printf("%d",arr[i]);
      break;
      }
     for(i++;i< n;i++)
     {
    if(used[i])
      System.out.printf("+%d",arr[i]);
      }
      System.out.println("");
    return;
     }
     for(i=now;i< n;i++)
     {
    if(total+arr[i]>sum) continue;
    if(i>0&&arr[i]==arr[i-1]&&!used[i-1]) continue;
    used[i]=true;
    f(i+1,total+arr[i]);
    used[i]=false;
      }
   }
public static void main(String args[])
{
   Scanner sc=new Scanner(System.in);
   while(true)
   {
    sum=sc.nextInt();
    n=sc.nextInt();
   if(n==0) break;
    FLAG=0;
   for(j=0;j< n;j++)
     arr[j]=sc.nextInt();
   System.out.printf("Sums of %d:n",sum);
   f(0,0);
   if(FLAG==0) System.out.println("NONE");
   }
  }
}