双向链表增删改查

package com.dai.linkedList;

import javax.lang.model.element.NestingKind;

public class DoubleLinkedListDemo {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        //双向链表的测试
        System.out.println("双向链表的测试");
        HeroNode2 hero1 = new HeroNode2(1, "宋江", "及时雨");
        HeroNode2 hero2 = new HeroNode2(2, "卢俊义", "玉麒麟");
        HeroNode2 hero3 = new HeroNode2(3, "吴用", "智多星");
        HeroNode2 hero4 = new HeroNode2(4, "林冲", "豹子头");
        
        //创建一个双向链表对象
        DoubleLinkedList doubeLinkedList = new DoubleLinkedList();
        doubeLinkedList.add(hero1);
        doubeLinkedList.add(hero2);
        doubeLinkedList.add(hero3);
        doubeLinkedList.add(hero4);
        
        doubeLinkedList.list();
        
        //修改
        HeroNode2 newHeroNode = new HeroNode2(4, "公孙胜", "入云龙");
        doubeLinkedList.update(newHeroNode);
        System.out.println("修改后的链表：");
        doubeLinkedList.list();
        
        //删除
        doubeLinkedList.delete(3);
        System.out.println("删除后的");
        doubeLinkedList.list();
        
        //按顺序插入
        HeroNode2 hero5 = new HeroNode2(3,"测试", "测试昵称");
        doubeLinkedList.addByOrder(hero5);
        System.out.println("按顺序插入:");
        doubeLinkedList.list();
    }
}
class DoubleLinkedList{
    private HeroNode2 head = new HeroNode2(0, null, null);
    //返回头结点
    public HeroNode2 getHead() {
        return head;
    }
    //遍历双向链表的方法
    public void list() {
        //先判断链表是否为空
        if(head.next ==null) {
            System.out.println("链表为空");
            return;
        }
        HeroNode2 temp = head.next;
        while(true) {
            if(temp==null) {
                break;
            }
            //输出节点信息
            System.out.println(temp);
            temp = temp.next;
        }
    }
    //添加节点到最后
    public void add(HeroNode2 heroNode) {
        HeroNode2 temp = head;
        while(true) {
            if(temp.next==null) {
                break;
            }
            temp = temp.next;
        }
        temp.next = heroNode;
        heroNode.pre = temp;
    }
    public void addByOrder(HeroNode2 heroNode) {
        HeroNode2 temp = head;
        boolean flag = false;
        while(true) {
            if(temp.next==null) {
                break;
            }
            if(temp.next.no > heroNode.no) {
                break;
            }
            else if (temp.next.no == heroNode.no) {
                flag = true;
                break;
            }
            temp = temp.next;
        }
        if(flag==true) {
            System.out.println("英雄编号存在，非法插入");
            return;
        }
        if(temp.next == null) {
            temp.next = heroNode;
            heroNode.pre = temp;
        }
        else {
            heroNode.pre = temp;
            heroNode.next = temp.next;
            temp.next.pre = heroNode;
            temp.next = heroNode;
        }
        
    }
    //修改一个节点的内容
    public void update(HeroNode2 newHeroNode) {
        if (head.next==null) {
            System.out.println("链表为空");
            return;
        }
        HeroNode2 temp = head.next;
        boolean flag = false;
        while(true) {
            if(temp == null) {
                break;
            }
            if(temp.no == newHeroNode.no) {
                flag = true;
                break;
            }
        temp = temp.next;
        }
        if(flag) {
            temp.name = newHeroNode.name;
            temp.nickname = newHeroNode.nickname;
        }
        else {
            System.out.printf("没有找到编号%d的节点\n", newHeroNode.no);
        }
    }
    //双向链表可以直接找到要删除了节点，找到后自我删除即可
    public void delete(int no) {
        //判断当前链表是否空
        if(head.next==null) {
            System.out.println("链表空，无法删除");
            return;
        }
        
        HeroNode2 temp = head; //辅助指针
        boolean flag = false; //标识节点
        while (true) {
            if(temp == null) {
                break;
            }
            if(temp.no==no) {
                flag = true;
                break;
            }
            temp = temp.next;
        }
        if(flag == true) {
            temp.pre.next = temp.next;
            if(temp.next != null) {
                temp.next.pre = temp.pre;
            }
        }
        else {
            System.out.println("没找到要删除的节点呀");
        }
    }
}
//创建一个双向链表的类
class HeroNode2{
    public int no;
    public String name;
    public String nickname;
    public HeroNode2 next;
    public HeroNode2 pre;
    
    public HeroNode2(int no, String name, String nickname) {
        this.no = no;
        this.name = name;
        this.nickname = nickname;
    }

    @Override
    public String toString() {
        return "HeroNode2 [no=" + no + ", name=" + name + ", nickname=" + nickname + "]";
    }
    
    
}