单向环形链表

• 双向环形链表自己扩展

//小孩节点
@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
public class Child {
    //序号
    private Integer no;
    //下一个节点
    private Child next;
    public Child(Integer no) {
        this.no = no;
    }
}

//单向环形列表
public class SingleLinkedList {
    private static Child first = new Child(1);
    static {
        first.setNext(first);
    }
    //添加小孩节点 , 构建环形列表
    public void addChild(Integer newNo){addChildR(first,newNo);}
    private void addChildR(Child child,Integer newNo){
        if(child.getNo() == newNo){
            System.out.println("编号重复");
            return;
        }
        if(child.getNext().getNo() != first.getNo()){
            addChildR(child.getNext(),newNo);
        }else{
            Child child1 = new Child(newNo);
            child1.setNext(first);
            child.setNext(child1);
        }
    }
    //遍历
    public void childList(){ childListR(first);}
    private void childListR(Child child){
        System.out.printf("编号: %d",child.getNo());
        System.out.println();
        if(child.getNext().getNo() != first.getNo()){
            childListR(child.getNext());
        }else{
            return;
        }
    }
    /**
     * 数小孩 出圈
     * @param starNo  表示从第几个小孩开始数
     * @param countNum 表示数几下
     */
    public void childCount(int starNo,int countNum){childCountR(getChild(starNo),countNum,0,getChild(childSum()));}
    /**
     *
     * @param child
     * @param countNum 需要数几下
     * @param countNumnow 当前数了几次
     */
    private void childCountR(Child child,int countNum,int countNumnow,Child pre){
        if(countNum == countNumnow+1){
            System.out.printf("编号: %d",child.getNo());
            System.out.println();
            //出圈
            pre.setNext(child.getNext());
            countNumnow = 0;
        }else{
            countNumnow++;
        }
        if(child.getNext().getNo() != child.getNo()){
            childCountR(child.getNext(),countNum,countNumnow,child);
        }else{
            System.out.printf("编号: %d",child.getNext().getNo());
            System.out.println();
        }
    }
    public Child getChild(int counNum){ if(counNum<=0) counNum=1;return getChildR(first,counNum,1);}
    /**
     * 获取正数第 n 个小孩节点
     * @param child
     * @param counNum 需要数到第几个
     * @param counNumNow 当前数到多少
     * @return
     */
    private Child getChildR(Child child,int counNum,int counNumNow){
        if(counNum != counNumNow){
            counNumNow++;
            return getChildR(child.getNext(),counNum,counNumNow);
        }else{
           return child;
        }
    }
    //获取总结点数量
    public int childSum(){ return childSumR(first,1); }
    private int childSumR(Child child,int count){
        if(child.getNext().getNo() != first.getNo()){
            count++;
            return childSumR(child.getNext(),count);
        }else{
            return count;
        }
    }
}

public class Test {
    public static void main(String[] args) {
        SingleLinkedList singleLinkedList = new SingleLinkedList();

        singleLinkedList.addChild(2);
        singleLinkedList.addChild(3);
        singleLinkedList.addChild(4);
        singleLinkedList.addChild(5);
        singleLinkedList.addChild(6);

        singleLinkedList.childList();
        System.out.println("--------------------------");
        singleLinkedList.childCount(1,2);

        Child child = singleLinkedList.getChild(5);
    }
}