双向链表

java数据结构与算法学习记录----双向链表
双向查找（向前，向后）
可自我删除（单链表删除总是找前一个结点）

双向链表增删查改

package linkedlist;

/**
 * 双向链表
 * @author jk
 *
 */
public class DoubleLinkedList {

	public static void main(String[] args) {
		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");
		DoubleLinkedListDome doubleLinkedListDome=new DoubleLinkedListDome();
		
//		doubleLinkedListDome.add(hero1);
//		doubleLinkedListDome.add(hero4);
//		doubleLinkedListDome.add(hero3);
//		doubleLinkedListDome.add(hero2);
//		doubleLinkedListDome.display_list();
		
		doubleLinkedListDome.addByOrder(hero1);
		doubleLinkedListDome.addByOrder(hero4);
		doubleLinkedListDome.addByOrder(hero3);
		doubleLinkedListDome.addByOrder(hero2);
		doubleLinkedListDome.display_list();
		
		HeroNode2 heroNode2=new HeroNode2(4, "Vecter","猜不透" );
		doubleLinkedListDome.Update(heroNode2);
		System.out.println("更新后链表");
		doubleLinkedListDome.display_list();
		
		doubleLinkedListDome.del(1);
		System.out.println("删除后链表");
		doubleLinkedListDome.display_list();
	}

}

class DoubleLinkedListDome{
	private HeroNode2 head =new HeroNode2(0, "", "");
	
	public HeroNode2 getHead() {
		return head;
	}
	
	//显示链表（遍历）
	public void display_list() {
		if (head.next==null) {
			System.out.println("链表为空");
			return;
		}
		HeroNode2 temp=head.next;
		while(true) {
			if(temp==null) {
				break;
			}
			System.out.println(temp);
			temp=temp.next;
		}
	}
	
	//按排名添加
	public void addByOrder(HeroNode2 heroNode2) {
		HeroNode2 temp=head;
		boolean flag=false;
		
		while(true) {
			if (temp.next==null) {
				break;
			}
			if(temp.next.on>heroNode2.on) {
				break;
			}else if(temp.next.on==heroNode2.on){
				flag=true;
				break;
			}
			temp=temp.next;
		}
		if(flag) {
			System.out.printf("编号%d节点已存在",heroNode2.on);
		}else {
			heroNode2.next=temp.next;
			temp.next=heroNode2;
			heroNode2.pre=temp;
		}
	}
	
	//添加结点到链表最后
	public void add(HeroNode2 heroNode2) {
		HeroNode2 temp=head;
		while(true) {
			if(temp.next==null) {
				break;
			}
			temp=temp.next;
		}
		temp.next=heroNode2;
		heroNode2.pre=temp;
	}
	
	//修改节点内容
	public void Update(HeroNode2 newHeroNode2) {
		if(head.next==null) {
			System.out.println("链表无数据");
			return;
		}
		HeroNode2 temp=head.next;
		boolean flag=false;
		while(true) {
			if(temp==null) {
				break;
			}
			if(temp.on==newHeroNode2.on) {
				flag=true;
				break;
			}
			temp=temp.next;
		}
		if (flag) {
			temp.name=newHeroNode2.name;
			temp.nickname=newHeroNode2.nickname;
		}else {
			System.out.printf("无编号为%d节点\n",newHeroNode2.on);
		}
	}
	
	//删除节点
	public void del(int on) {
		if (head.next==null) {
			System.out.println("链表无数据");
			return;
		}
		HeroNode2 temp=head.next;
		boolean flag=false;
		while(true) {
			if (temp==null) {
				break;
			}
			if(temp.on==on) {
				flag=true;
				break;
			}
			temp=temp.next;
		}
		if (flag) {
			temp.pre.next=temp.next;
			if(temp.next!=null) {
				temp.next.pre=temp.pre;
			}
		}else {
			System.out.printf("要删除的%d节点不存在\n",on);
		}
	}
}

class HeroNode2{
	public int on;
	public String name;
	public String nickname;
	public HeroNode2 next;
	public HeroNode2 pre;
	
	public HeroNode2(int on,String name,String nickname) {
		this.name=name;
		this.on=on;
		this.nickname=nickname;
	}
	@Override
	public String toString() {
		return "HeroNode [on=" + on + ", name=" + name + ", nickname=" + nickname + "]";
	}
}

标签：temp,双向,next,链表,public,HeroNode2,heroNode2,doubleLinkedListDome
来源： https://blog.csdn.net/weixin_44565065/article/details/114555012