content: /*
   *    This program 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.
   *
   *    This program 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 this program; if not, write to the Free Software
   *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  /*
   *    SMOset.java
   *    Copyright (C) 1999 University of Waikato, Hamilton, New Zealand
   *
   */
  
  package weka.classifiers.functions.supportVector;
  
  import weka.core.RevisionHandler;
  import weka.core.RevisionUtils;
  
  import java.io.Serializable;
  
  /**
   * Stores a set of integer of a given size.
   * 
   * @author Eibe Frank (eibe@cs.waikato.ac.nz)
   * @version $Revision: 1.5 $
   */
  public class SMOset
    implements Serializable, RevisionHandler {
  
    /** for serialization */
    private static final long serialVersionUID = -8364829283188675777L;
    
    /** The current number of elements in the set */
    private int m_number;
  
    /** The first element in the set */
    private int m_first;
  
    /** Indicators */
    private boolean[] m_indicators;
  
    /** The next element for each element */
    private int[] m_next;
  
    /** The previous element for each element */
    private int[] m_previous;
  
    /**
     * Creates a new set of the given size.
     */
    public SMOset(int size) {
        
      m_indicators = new boolean[size];
      m_next = new int[size];
      m_previous = new int[size];
      m_number = 0;
      m_first = -1;
    }
   
    /**
     * Checks whether an element is in the set.
     */
    public boolean contains(int index) {
  
      return m_indicators[index];
    }
  
    /**
     * Deletes an element from the set.
     */
    public void delete(int index) {
  
      if (m_indicators[index]) {
        if (m_first == index) {
  	m_first = m_next[index];
        } else {
  	m_next[m_previous[index]] = m_next[index];
        }
        if (m_next[index] != -1) {
  	m_previous[m_next[index]] = m_previous[index];
        }
        m_indicators[index] = false;
        m_number--;
      }
    }
  
    /**
     * Inserts an element into the set.
     */
    public void insert(int index) {
  
      if (!m_indicators[index]) {
        if (m_number == 0) {
  	m_first = index;
  	m_next[index] = -1;
  	m_previous[index] = -1;
        } else {
  	m_previous[m_first] = index;
  	m_next[index] = m_first;
  	m_previous[index] = -1;
  	m_first = index;
        }
        m_indicators[index] = true;
        m_number++;
      }
    }
  
    /** 
     * Gets the next element in the set. -1 gets the first one.
     */
    public int getNext(int index) {
  
      if (index == -1) {
        return m_first;
      } else {
        return m_next[index];
      }
    }
  
    /**
     * Prints all the current elements in the set.
     */
    public void printElements() {
  
      for (int i = getNext(-1); i != -1; i = getNext(i)) {
        System.err.print(i + " ");
      }
      System.err.println();
      for (int i = 0; i < m_indicators.length; i++) {
        if (m_indicators[i]) {
  	System.err.print(i + " ");
        }
      }
      System.err.println();
      System.err.println(m_number);
    }
  
    /** 
     * Returns the number of elements in the set.
     */
    public int numElements() {
        
      return m_number;
    }
    
    /**
     * Returns the revision string.
     * 
     * @return		the revision
     */
    public String getRevision() {
      return RevisionUtils.extract("$Revision: 1.5 $");
    }
  }
  