duolinklist.java

基本数据结构

package DuoLink;

public class DuoLinkList 
{

    private DuoLinkItem Start=null;
    private DuoLinkItem End=null;
    private DuoLinkItem Current=null;
    public DuoLinkList(Object item)
    {
    	if(item!=null) 
    	{
    		Current=Start=End=new DuoLinkItem(item);
    	}
    }
    public void clear()
    {
    	Current=null;
    	End=null;
    	Start=null;
    }
    public DuoLinkItem getFirst()
    {
    	Current=Start;
    	return Start==null?null:Start;
    }
    public DuoLinkItem getNext()
    {
    	if(Current!=null){Current=Current.next;}
    	return Start==null?null:Current;
    }
    public int getLength(DuoLinkItem Start)
    {
    	int i;
    	for(i=1;i>0;i++)
    	{
    		if(Start.item!=null&&Start.next!=null){Start=Start.next;}
    		else break;
    	}
    	return i;
    }
    public int getIndex(Object item)
    {
    	int i; Current=Start;
    	for(i=0;i<this.getLength(this.getFirst());i++)
    	{
    		if(item==Current.item)break;
    		if(item!=Current.item)
    		{
    			Current=Current.next;
    		}
    		if(Current.next==null)
    		{
    			Current=Start;
    			System.out.println("The item is not exist!");
    			i=-1;
    		}
    	}
		return i;
    }
    public boolean equals(DuoLinkList linkStart1,DuoLinkList linkStart2)
	{
        if(!linkStart1.getItemArray().equals(linkStart2.getItemArray())) return false;
        else return true;
	}
    public Object[] getItemArray()
    {
    	Object[] items=new Object[this.getLength(this.getFirst())];
    	for(int i=0;i<this.getLength(this.getFirst());i++)
    	{
    		items[i]=Start.item;
    		Start=Start.next;
    	}
    	return items;
    }
    public DuoLinkList intl(Object[] items)
    {
    	if(items!=null)
    	{
    		for(int i=0;i<items.length;i++) intlItem(items[i]);
    		Current=Start;
    	}
    	return this;
    }
    public void intlItem(Object item)
    {
    	DuoLinkItem newEnd=new DuoLinkItem(item); 
    	if(Start==null)
    	{
    		Start=End=newEnd;
    	}
    	else
    	{
    		End.next=newEnd;
    		End=newEnd;
    	} 
    }
    public DuoLinkItem searchItem(Object item)
    {
    	int i; Current=Start;
    	for(i=0;i<this.getLength(this.getFirst());i++)
    	{
    		if(item==Current.item)
    		{
    			System.out.println("The item is found!It's:");
    		}
    		if(item!=Current.item)
    		{
    			Current=Current.next;
    		}
    		if(Current.next==null)
    		{
    			Current=Start;
    			System.out.println("The item is not found!The start item is:");
    			break;
    		}
    	}
		return Current;
    }
    public DuoLinkList removeItem(Object item)
    {
    	int i;
    	Current=this.searchItem(item);
    	for(i=this.getIndex(item);i<this.getLength(this.getFirst());i++)
    	{
    		Current=Current.next;
    	}
    	DuoLinkList newLinkList=new DuoLinkList(this.getItemArray());
    	return newLinkList;
    }
    public DuoLinkList insertItem(Object item,Object insert)
    {
    	int i;DuoLinkItem newItem=new DuoLinkItem(insert);
    	Current=this.searchItem(item);
    	if(Current==Start||Current==null)
    	{
    		System.out.println("Can't find the item.Can't insert!Please input again");
    		return this;
    	}
    	else
    	{
    		newItem.last=Current.last;
    		newItem.next=Current.next;
    	}
    	return this;
    }
    public String toString()
    {
    	System.out.println("The Link is:");
    	Object[] items=new Object[this.getLength(this.getFirst())];
    	items=this.getItemArray();
    	StringBuffer b = new StringBuffer(items.length*7);
		b.append("[");
		for(int i=0;i<this.getLength(this.getFirst());i++)
			if (items[i] == null)
				b.append("null, ");
			else
				b.append(items[i].toString() + ", ");
		if (items.length > 0)
			b.delete(b.length() - 2, b.length());
		b.append(")");
		return new String(b);

    }
}