算法学习(8)-链表之双端链表

package com.tw.dst.link;/** * <p>链表学习(二):双端链表</p> * @author tangw 2010-12-07 * */public class FirstLastLink {private Link first; //第一个链表引用private Link last; //最后一个链表引用//判断是否为空public boolean isEmpty(){return (first==null);}//在表前插入一个链结点public void insertFirst(int id,double dd){Link newLink = new Link(id,dd);if(this.isEmpty()){last = newLink;}newLink.next = first;first = newLink; }//在表尾插入一个链结点public void insertLast(int id,double dd){Link newLink = new Link(id,dd);if(this.isEmpty()){first = newLink;}last.next = newLink;last = newLink; }//删除第一个链结点public Link deleteFirst(){Link temp = first;if(first == null){last  = null;}first = first.next;return temp;}//输出链表数据public void displayList(){System.out.println("list (first-->last)");Link current = first;while(current!=null){current.displayLink();current =current.next;}System.out.println("");}/** * @param args */public static void main(String[] args) {//----1---插入FirstLastLink linkList = new FirstLastLink();linkList.insertFirst(22, 2.99);linkList.insertFirst(44, 4.99);linkList.insertFirst(66, 6.99);linkList.displayList();//---2---删除Link aLink = linkList.deleteFirst();linkList.displayList();}}

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