q1.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication3
{
    class My
    {
        public static void Main()
        {

            ////creating
            //MyPoint p = new MyPoint();
            //MyPoint k = new MyPoint();
            //MyPoint l = new MyPoint { X = 1, Y = 2, Z = 3 };
            //MyPoint n = new MyPoint { X = 1, Y = 2, Z = 3 };
            //MyPoint a = l;

            ////viewing
            //Console.WriteLine(p.ToString());
            //Console.WriteLine(l.ToString());

            ////equality
            ////Console.WriteLine(l.Equals(n));
            ////Console.WriteLine(p.Equals(n));
            //Console.WriteLine("\n");
            //Console.WriteLine(Object.Equals(l, n));
            //Console.WriteLine(Object.Equals(l, a));

            ////hash
            //Console.WriteLine(l.GetHashCode());

            MyPoint a1 = new MyPoint();
            a1.FillArray(10);
            foreach (MyPoint x in a1)
                Console.WriteLine(x.X);
            
            Console.ReadLine();
        }
    }

    class MyPoint : IEnumerable
    {
        int x;
        int y;
        int z;

        MyPoint[] arr;

        public int X
        {
            get { return x;  }
            set { x = value; }
        }

        public int Y
        {
            get { return y; }
            set { y = value; }
        }

        public int Z
        {
            get { return z; }
            set { z = value; }
        }

        public MyPoint()
        {
            Random r = new Random();
            x = r.Next(1, 101);
            y = r.Next(1, 101);
            z = r.Next(1, 101);
        }

        public MyPoint(int x, int y, int z)
        {
            X = x;
            Y = y;
            Z = z;
        }

        //public IEnumerator GetEnumerator()
        //{
        //    return arr.GetEnumerator();
        //}

        //public IEnumerator GetEnumerator()
        //{
        //    foreach (MyPoint item in arr)
        //    {
        //        yield return item;
        //    }
        //}

        public IEnumerator GetEnumerator()
        {
            return new MyEnumerator(this);
        }

        public IEnumerable GetPoints(bool b)
        {
            return new MyEnumerable(this);
        }

        class MyEnumerable : IEnumerable
        {
            MyPoint p;

            public MyEnumerable(MyPoint p)
            {
                this.p = p;
            }

            public IEnumerator GetEnumerator()
            {
                return MyPoint.MyEnumerator e = new MyPoint.MyEnumerator();
            }
        }

        class MyEnumerator : IEnumerator
        {
            MyPoint[] arr;
            int len;
            int i;

            public MyEnumerator(MyPoint x)
            {
                arr = x.arr;
                len = x.arr.Length;
                i = 0;
            }

            public bool MoveNext()
            {
                return i != len ? true : false;
            }

            public object Current
            {
                get
                {
                    return arr[i++];
                }
            }

            public void Reset()
            {
                i = 0;
            }
        }

        public void FillArray(int n)
        {
            arr = new MyPoint[n];
            for (int i = 0; i < n; i++)
                arr[i] = new MyPoint { X = i, Y = i + 1, Z = i + 2 };
        }
        
        public override string ToString()
        {
            return String.Format("First field = {0}\nSecond field = {1}\nThird field = {2}\n", x, y, z);
        }

        public override bool Equals(object obj)
        {
            MyPoint p = obj as MyPoint;
            if (p != null)
            {
                if (this.x == p.x && this.y == p.y && this.Z == p.Z)
                    return true;
            }

            return false;
        }

        public override int GetHashCode()
        {
            return this.ToString().GetHashCode();
        }
    }

}