双向链表 --java实现

抽象表:

package edu.cquptzx.List;
publicinterface List
{
publicvoid insert(int i ,Object obj)
throws Exception;
//插入
public Object delete(int i )
throws Exception;                
//删除
public Object getData(int i )
throws Exception;               
//获取i元素
publicint size();                                         
//表数据总数
publicboolean isEmpty();                                  
//是否为空
}

节点

package edu.cquptzx.List;

publicclass TNode
{
    TNode prior;
    Object element;
    TNode next;
    TNode( TNode nextval)
    {  
prior = nextval;
next = nextval;  

    }
    TNode(TNode priorval,Object obj,TNode nextval)
    {
prior = priorval;
element = obj;
next = nextval;     

    }
public TNode getPrior()
    {
returnprior;
    }
publicvoid setPrior(TNode priorval)
    {
prior = priorval;
    }
public TNode getNext()
    {
returnnext;
    }
publicvoid setNext(TNode nextval)
    {
next = nextval;
    }
public Object getElement()
    {
returnelement;
    }
publicvoid setElement(Object obj)
    {
element = obj;
    }
public String toString()
    {
returnelement.toString();
    }
}

双向链表实现:

/**
*
*/
package edu.cquptzx.List;

/**
* @author cquptzx
*
*/
publicclass DoubleLinkList
implements List {

    TNode head;
    TNode current;
intsize;
/**
     * 构造函数:
     * 初始化循环链表.
     */
    DoubleLinkList()
    {
head=current=new TNode(null);
head.<
4000
/span>prior=head;
head.next=head;
size = 0;
    }
/**
     * 定位成员函数index(int i)的实现
     * 循环从头开始查找,循环的条件是:1.定位完成j==i;2.链表查找结束了.
     * @param i
     * @throws Exception
当参数i错误时,抛出异常.
     */
publicvoid index(int i )throws
Exception
    {
if(i<-1 || i >size-1)
       {
thrownew Exception("i error in INDEX of DoubleLinkList.");
       }
if(i == -1)
return;
current =
head.next;
int j = 0;
while(current!=head && j<i)
       {
current =
current.next;
           j++;
       }
    }
/* (non-Javadoc)
     * @see edu.cquptzx.List.List#insert(int, java.lang.Object)
     */
@Override
publicvoid insert(int i, Object obj)
throws Exception

    {
// TODO Auto-generated method stub
if(i<0 || i>size)
       {
thrownew Exception ("i error in INSERT.");
       }
       index(i-1);
current.setNext(new TNode(current.getNext(),obj,current.next.getPrior()));
current.next.next.setPrior(current.next.getNext());
size++;   

    }

/* (non-Javadoc)
     * @see edu.cquptzx.List.List#delete(int)
     */
@Override
public Object delete(int i)
throws Exception {
// TODO Auto-generated method stub
if(size == 0)
       {
thrownew Exception ("Link Blank in DELETE.");
       }
if(i<0 || i>size-1)
       {
thrownew Exception ("i error in DELETE.");
       }
       index(i-1);
       Object obj = current.next.getElement();
current.setNext(current.next.next);
current.next.setPrior(current.getNext());
size--;
return obj;
    }

/* (non-Javadoc)
     * @see edu.cquptzx.List.List#getData(int)
     */
@Override
public Object getData(int i)
throws Exception {
// TODO Auto-generated method stub
if(i<-1 || i>size-1)
       {
thrownew Exception ("i error in getData.");
       }
       index(i);
returncurrent.getElement();
    }

/* (non-Javadoc)
     * @see edu.cquptzx.List.List#size()
     */
@Override
publicint size() {
// TODO Auto-generated method stub
returnsize;
    }

/* (non-Javadoc)
     * @see edu.cquptzx.List.List#isEmpty()
     */
@Override
publicboolean isEmpty() {
// TODO Auto-generated method stub
returnsize == 0;
    }

}

双向链表输出测试:

package edu.cquptzx.List;

publicclass DoubleLinkListTest

{
publicstaticvoid main(String agrs[])
    {
       DoubleLinkList doubleLinkList =
new DoubleLinkList();
int n = 10;
try
       {
for(int i = 0;i<n;i++)
           {
              doubleLinkList.insert(i,
new Integer(i+1));
           }
           doubleLinkList.delete(4);
for(int i = 0;i<doubleLinkList.size;i++)
           {
              System.out.print(doubleLinkList.getData(i)+" ->");
           }
       }
catch(Exception e)
       {
           System.out.println(e.getMessage());
       }  
    }
}