code: //==============================================================================
  //	
  //	Copyright (c) 2002-
  //	Authors:
  //	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford)
  //	
  //------------------------------------------------------------------------------
  //	
  //	This file is part of PRISM.
  //	
  //	PRISM is free software; you can redistribute it and/or modify
  //	it under the terms of the GNU General Public License as published by
  //	the Free Software Foundation; either version 2 of the License, or
  //	(at your option) any later version.
  //	
  //	PRISM is distributed in the hope that it will be useful,
  //	but WITHOUT ANY WARRANTY; without even the implied warranty of
  //	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  //	GNU General Public License for more details.
  //	
  //	You should have received a copy of the GNU General Public License
  //	along with PRISM; if not, write to the Free Software Foundation,
  //	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //	
  //==============================================================================
  
  package pta;
  
  import java.util.*;
  
  public class LocZoneSet
  {
  	private HashMap<LocZone, Integer> set;
  	private int indexOfLastAdd;
  
  	public LocZoneSet()
  	{
  		set = new HashMap<LocZone, Integer>();
  		indexOfLastAdd = -1;
  	}
  
  	public boolean add(int loc, Zone z)
  	{
  		return add(new LocZone(loc, z));
  	}
  
  	public boolean add(LocZone lz)
  	{
  		Integer i = set.get(lz);
  		if (i != null) {
  			indexOfLastAdd = i;
  			return false;
  		} else {
  			indexOfLastAdd = set.size();
  			set.put(lz, set.size());
  			return true;
  		}
  	}
  
  	public boolean contains(LocZone lz)
  	{
  			return set.get(lz) != null;
  	}
  
  	public int getIndexOfLastAdd()
  	{
  		return indexOfLastAdd;
  	}
  
  	public boolean isEmpty()
  	{
  		return set.isEmpty();
  	}
  
  	public int size()
  	{
  		return set.size();
  	}
  
  	public ArrayList<LocZone> toArrayList()
  	{
  		int i, n;
  
  		n = set.size();
  		ArrayList<LocZone> list = new ArrayList<LocZone>(n);
  		for (i = 0; i < n ; i++)
  			list.add(null);
  		for (Map.Entry<LocZone, Integer> e : set.entrySet()) {
  			list.set(e.getValue(), e.getKey());
  		}
  		return list;
  	}
  
  	public String toString()
  	{
  		String s = "";
  		s += set;
  		return s;
  	}
  }
  