twothreenodeuos.java

国外的数据结构与算法分析用书

/* TwoThreeNodeUos.java
 * ---------------------------------------------
 * Copyright (c) 2001 University of Saskatchewan
 * All Rights Reserved
 * --------------------------------------------- */

package dslib.dictionary.twothreetree;

import dslib.base.*;
import java.io.Serializable;

/**	A node for a two-three tree.  It has a key instance variable,
	the methods search, insert, and delete, and a formatted output. */
public abstract class TwoThreeNodeUos implements Cloneable, Serializable
{

	/**	The parent node of this subtree */
	protected TwoThreeInteriorUos parent;

	/**	The parent of this node. <br> 
		Analysis: Time = O(1) */
	public TwoThreeInteriorUos parent()
	{
		return parent;
	}

	/**	Set the parent equal to y. <br> 
		Analysis: Time = O(1) 
		@param y The new parent */
	public void setParent(TwoThreeInteriorUos y)
	{
		parent = y;
	}

	/**	Search for the item with key i */
	public abstract void search(Comparable i, TwoThreeKeyedDictUos treeHeader);

	/**	Should insert object y and returns the extra node  */
	public abstract PairUos insert(KeyedUos y);

	/**	Delete the item with key i */
	public abstract boolean delete(Comparable i);

	/**	String representation of the contents of the node with indentation
		for different levels of the tree */
	public abstract String formatToString(String indentation);

	/**	A shallow clone of this object. <br> 
		Analysis: Time = O(1) */
	public Object clone()
	{
		try
		{
			return super.clone();
		} catch (CloneNotSupportedException e)
		{
			// Should not occur: implements Cloneable 
			e.printStackTrace();
			return null;
		}
	}
}