循环链表解决约瑟夫问题

定义人类结构体

public class people {
    int num;
    people next;

    public people(int num) {
        this.num = num;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    public people getNext() {
        return next;
    }

    public void setNext(people next) {
        this.next = next;
    }
}

核心代码

public class JosefulLikeList {
        people head;
        public void addpeople(int num)
        {
            if(num<1)
            {
                System.out.println("人数不符合开始规定");
                return;
            }
            people pos=null;
            for(int i=1;i<=num;i++)
            {
               people people= new people(i);
                if(i==1)
                {
                    head = people;
                    pos=head;
                    head.next=head;
                }
                else
                {
                    pos.next=people;
                    people.next=head;
                    pos=people;
                }
            }
        }
        public void showLikelist()
        {
            if(head.next==null)
            {
                System.out.println("不符合规定");
                return;
            }
            people pos=head;
            while(true)
            {
                System.out.println(pos.num);
                if(pos.next==head)
                {
                    break;
                }
                pos=pos.next;
            }
        }
        public void chuquan(int startnum,int all,int ci)
        {

            if(head.next==null||startnum<1||startnum>all)
            {
                System.out.println("不符合标准");
                return;
            }
            people helper=head;
            while(true)
            {
                if(helper.next==head)
                {
                    System.out.println("找到了head的上一个人");
                    break;
                }
                helper=helper.next;
            }
            for(int i=1;i<startnum;i++)
            {
                head=head.next;
                helper=helper.next;
            }
            while(true)
            {
                if(head==helper)
                {
                    System.out.println(head.num);
                    break;
                }
                for(int i=1;i<ci;i++)
                {
                    head=head.next;
                    helper=helper.next;
                }
                System.out.printf("第%d号出圈\n",head.num);
                head=head.next;
                helper.next=head;
            }
            System.out.printf("最后留下来的是%d",head.num);
        }
}

测试

public class test {
    public static void main(String[] args) {
        JosefulLikeList josefulLikeList = new JosefulLikeList();
        josefulLikeList.addpeople(5);
        josefulLikeList.showLikelist();
        josefulLikeList.chuquan(1,5,2);
    }
}