Circle逢3退出问题

//
/**//*
 * 17个人围成一圈，从第一个人开始报数，报到3的退出,最后剩下几
 */
using System;
using System.Collections.Generic;
using System.Text;

namespace Design_Pattern.Observer
{
    class circle2
    {
        static void Main(string[] args)
        {

            PersonList psl = new PersonList();
            psl.InitList();
            psl.Play();
            psl.Show();

            Console.ReadLine();

        }
    }
    class PersonList
    {
        List<person> list = new List<person>();

        public void InitList()
        {

            for (int i = 1; i <= 17; i++)
            {
                if (i > 1)
                {
                    //list.Add(new person(i, "张三" + i.ToString(), list.Find(delegate(person p) { return p.ID == i - 1; }).ID));
                    list.Add(new person(i, "Hello" + i.ToString(), list[i-2].ID));
                   // Console.WriteLine(list[i]);
                }
                else
                {
                    list.Add(new person(i, "Hello" + i.ToString(), 0));
                    
                }
                //Console.WriteLine(list[i]);

            }
            //list.Find(delegate(person p) { return p.ID == 1; }).ParentId = list.Find(delegate(person p) { return p.ID == list.Count; }).ID;
            list[0].ParentId = list[16].ParentId;
            

        }

        /**//// <summary>
        /// 最后剩下的两个数字
        /// </summary>
        public void Show()
        {
            foreach (person prs in list)
            {
                Console.WriteLine("ID:" + prs.ID);
                Console.WriteLine("Name:" + prs.Name);
                Console.WriteLine("ParentId:" + prs.ParentId.ToString());
            }

        }
        public void Play()
        {
            int Intex = 2;

            // 无限循环
            for (; ; )
            {
                if (list.Count >= 3)
                {

                    Remove(Intex);

                    Intex += 2;
                    if (Intex >= list.Count)
                        Intex = Intex - list.Count;

                }
                else
                {
                    break;
                }
            }
        }
        private void Remove(int index)
        {
            int index1 = index, index2 = index;
            if (index == this.list.Count - 1)
                index1 = -1;
            if (index == 0)
                index2 = this.list.Count;

            list[++index1].ParentId = list[--index2].ID;
            list.RemoveAt(index);

        }

    }


    class person
    {
        int id;
        string name;
        int parentid;

        public person()
        {

        }
        public person(int id, string name, int parentId)
        {
            this.id = id;
            this.name = name;
            this.parentid = parentId;
        }
        public int ID
        {
            get
            {
                return id;
            }
            set
            {
                id = value;
            }
        }
        public string Name
        {
            get
            {
                return name;
            }
            set
            {
                name = value;
            }

        }
        public int ParentId
        {
            get
            {
                return parentid;
            }
            set
            {
                parentid = value;
            }
        }
    }
}