1.

package contestVolumes.volume109;

import java.util.HashSet;
   import java.util.LinkedList;
   import java.util.Scanner;
   import java.util.Set;

/**
   * FWP, Ausgewählte Probleme aus dem ACM Programming Contest, SS10 
   * Problem: 10930 - A-Sequence
   * Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=21&page=show_problem&problem=1871
   * 
   * @author Siegfried Ippisch
   * @version 1.0
   * 
   * Method : -
   * Status : Accepted
   * Runtime: 0.240
   */
   public class ASequence {
   
   public static void main(String[] args){
   Scanner in = new Scanner(System.in);
   int c = 1;
   
   while(in.hasNext()){
   int n = in.nextInt();
   LinkedList<Integer> list = new LinkedList<Integer>();
   for(int i=0; i<n; i++)
   list.add(in.nextInt());
   
   System.out.println("Case #"+ c++ +":"+listToString(list));
   System.out.println(aSequence(list) ? "This is an A-sequence.": "This is not an A-sequence.");
   }
   
   in.close();
   }
   
   private static String listToString(LinkedList<Integer> list) {
   String s = "";
   for(int i: list)
   s = s + " " + i;
   return s;
   }

 public static boolean aSequence(LinkedList<Integer> list){
   Set<Integer> sum = new HashSet<Integer>();
   sum.add(list.removeFirst());
   
   int last = 0;
   while(!list.isEmpty()){
   int a = list.removeFirst();
   
   if(a <= last)
   return false;
   
   if(sum.contains(a))
   return false;
   
   last = a;
   
   LinkedList<Integer> newSums = new LinkedList<Integer>();
   for(int s: sum)
   newSums.add(s+a);
   
   sum.add(a);
   sum.addAll(newSums);
   }
   
   return true;
   }
   }
 

2.

package acm_10930_a_sequence;


import java.util.ArrayList;
import java.util.LinkedList;
import java.util.ListIterator;
import java.util.Scanner;

/**
 * FWP, AusgewŠhlte Probleme aus dem ACM Programming Contest, SS10 
 * Problem: acm_10930_a_sequence
 * Link: 
 * 
 * @author Martin Lambeck
 * @version 1.0, 25.08.2010
 * 
 * Method : 
 * Status : Accepted
 * Runtime: 
 */


public class Main
{
	static Scanner sc = new Scanner(System.in);
	static int tcase = 0;
	
	public static void main(String... args)
	{
		while (testcase())
			;
	}

	public static boolean testcase()
	{
		if (!sc.hasNextInt())
			return false;
		
		int count = sc.nextInt();
		
		ArrayList<Integer> seq = new ArrayList<Integer>(count);
		boolean[] sum = new boolean[1001];
		LinkedList<Integer> lsum = new LinkedList<Integer>();
		
		StringBuilder str = new StringBuilder("");
		boolean fail = false;
		int prev = 0;
		
		for (int i = 0; i < count; i++)
		{
			int n = sc.nextInt();
			
			if (prev >= n)
				fail = true;
			
			seq.add(n);
			str.append(" " + n);
			prev = n;
		}

		
		if (!fail)
			for (int s : seq)
			{
				if (sum[s])
				{
					fail = true;
					break;
				}
				
				ListIterator<Integer> itr = lsum.listIterator();
				
				while (itr.hasNext())
				{
					int sl = s + itr.next();
					
					if ((sl <= 1000) && !sum[sl])
					{
						sum[sl] = true;
						itr.add(sl);
					}
				}
					
				lsum.add(s);
			}
		
		tcase++;
		

		System.out.printf("Case #%d:%s%nThis is %s A-sequence.%n", tcase, str, (fail ? "not an" : "an"));

		return true;
	}
}