20175324 数据结构-java实现

Posted 2021-11-27 wcqy

循环单链表-数据结构-java实现

目录

抽象表:1

循环单链表实现:1

循环单链表输出测试:4

输出结果:5

 

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

   

}

循环单链表实现:

package edu.cquptzx.List;

 

publicclass LoopLinkList implements List {

    Node head;

    Node current;

    intsize;

   

    LoopLinkList()

    {

       head = current = new Node(null);

       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.");

       }

       if(i == -1) return;

       current = head.next;

       int j = 0;

       while(current!=head && j<i)

       {

           current = current.next;

           j++;

       }

    }

    /**

     * 插入节点算法:

     * 1.调用index(i-1),让成员变量current指向第i-1个节点.

     * 2.以obj,current.next为参数创建新的节点.

     * 3.更改current指向,改为下一个节点.

     * 4.表元素总数加1.

     */

    publicvoid insert(int i, Object obj) throws Exception {

       if(i<0 || i>size)

       {

           thrownew Exception ("i error in INSERT.");

       }

       index(i-1);

       current.setNext(new Node(obj,current.next));

       size++;

    }

 

    /**

     * 删除节点算法:

     * 1.调用index(i-1),让成员变量current指向第i-1个节点.

     * 2.把第i个节点脱链:让第i-1个节点的next域等于第i个节点的next域.

     * 3.数据元素总数size减1.

     */

    public Object delete(int i) throws Exception {

       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);

       size--;

       return obj;

    }

    /**

     * 获取指定的元素

     * 1.调用index(i),让成员变量current指向第i个节点.

     * 2.返回该节点的数据域的值.

     */

    @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();

    }

 

    @Override

    publicint size() {

       // TODO Auto-generated method stub

       returnsize;

    }

 

    @Override

    publicboolean isEmpty() {

       // TODO Auto-generated method stub

       returnsize ==0;

    }

   

}

循环单链表输出测试:

package edu.cquptzx.List;

 

publicclass LoopLinkListTest

{

    publicstaticvoid main(String agrs[])

    {

       LoopLinkList lplklt = new LoopLinkList();

       int n = 10;

       try

       {

           for(int i = 0;i<n;i++)

           {

              lplklt.insert(i, new Integer(i+1));

           }

           lplklt.delete(4);

           for(int i = 0;i<lplklt.size;i++)

           {

              System.out.print(lplklt.getData(i)+"...end ");

           }

       }

       catch(Exception e)

       {

           System.out.println(e.getMessage());

       }

    }

}

 

输出结果: