数据结构学习（一）：单链表

一、单链表定义

class HeroNode {
    public int no;
    public String name;
    public String nickname;
    public HeroNode next;

    public HeroNode(int no, String name, String nickname) {
        this.no = no;
        this.name = name;
        this.nickname = nickname;
    }

    @Override
    public String toString() {
        return "HeroNode{" +
                "no=" + no +
                ", name='" + name + '\'' +
                ", nickname='" + nickname + '\'' +
                ", next=" + next +
                '}';
    }
}

二、添加节点

public void add(HeroNode heroNode) {
        HeroNode temp = head;
        //遍历链表，找到最后
        while (true) {
            if(temp.next == null) {
                break;
            }
            temp = temp.next;
        }
        //退出while时候,temp就指向了链表的最后,指向新的node
        temp.next = heroNode;
    }

三、按照顺序添加节点

//根据序号将node插入到指定位置
    public void addByOrder(HeroNode heroNode) {
        //头节点不能动，所以要一个辅助变量来遍历
        HeroNode temp = head;
        //标识添加的编号是否存在
        boolean flag = false;

        //遍历链表，找到最后
        while (true) {
            if(temp.next == null) {
                break;
            }

            //找到位置， 在temp后面插入
            if(temp.next.no > heroNode.no) {
                break;
            }else if(temp.next.no == heroNode.no) {//希望添加的node的编号已经存在
                flag = true;
                break;
            }
            temp = temp.next;
        }

        //判断flag的值
        if(flag) {//不能添加，说明编号存在
            System.out.println(heroNode.no + " cun zai");
        }else {
            //插入到链表中,temp的后面
            heroNode.next = temp.next;
            temp.next = heroNode;
        }
    }

四、按照顺序显示链表

public void list() {
        if(head.next == null) {
            System.out.println("null");
            return;
        }

        //头节点不能动，所以要一个辅助变量来遍历
        HeroNode temp = head.next;
        while (true) {
            if(temp == null) {
                break;
            }
            System.out.println(temp);
            temp = temp.next;
        }
    }

五、编辑节点

//修改节点信息，根据编号来改正，但编号不能改正
    public void update(HeroNode newHeroNode) {
        if(head.next == null) {
            System.out.println("LinkedList is null~~");
            return;
        }

        //定义一个辅助变量
        HeroNode temp = head.next;
        //是否找到要修改的变量
        boolean flag = false;

        while (true) {
            //已经遍历完链表
            if(temp == null) {
                break;
            }

            if(temp.no == newHeroNode.no) {
                //找到
                flag = true;
                break;
            }

            temp = temp.next;
        }

        //根据flag判断是否找到要修改的node
        if(flag) {
            temp.name = newHeroNode.name;
            temp.nickname = newHeroNode.nickname;
        }else {
            System.out.println("no find " + newHeroNode.no);
        }
    }

六、删除节点

 //删除节点
    public void del(int no) {
        HeroNode temp = head;
        //标识是否找到节点
        boolean flag = false;
        while (true) {
            if(temp.next == null) {
                break;
            }

            //找到待删除节点的前一个节点temp
            if(temp.next.no == no) {
                flag = true;
                break;
            }

            temp = temp.next;
        }

        if(flag) {
            temp.next = temp.next.next;
        }else {
            System.out.println("bu cun zai " + no);
        }
    }

七、定义头结点

private HeroNode head = new HeroNode(0, "", "");

八、测试

 public static void main(String[] args) {
        HeroNode heroNode1 = new HeroNode(1,"1","1");
        HeroNode heroNode2 = new HeroNode(2,"2","2");
        HeroNode heroNode3 = new HeroNode(3,"3","3");
        HeroNode heroNode4 = new HeroNode(4,"4","4");

        SingleLinkedList singleLinkedList = new SingleLinkedList();

//        //加入
//        singleLinkedList.add(heroNode1);
//        singleLinkedList.add(heroNode2);
//        singleLinkedList.add(heroNode3);
//        singleLinkedList.add(heroNode4);

        //按照编号加入
        singleLinkedList.addByOrder(heroNode1);
        singleLinkedList.addByOrder(heroNode4);
        singleLinkedList.addByOrder(heroNode3);
        singleLinkedList.addByOrder(heroNode2);
        singleLinkedList.addByOrder(heroNode1);

        singleLinkedList.list();

        System.out.println();

        //修改
        HeroNode newNode = new HeroNode(2, "22", "22");
        singleLinkedList.update(newNode);

        singleLinkedList.list();

        singleLinkedList.del(1);
        System.out.println();
        singleLinkedList.list();
    }