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

namespace Domino
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Random rnd = new Random();
            var list = new List<Domino>();

            list.Add(new Domino(1, 4));
            list.Add(new Domino(0, 2));
            list.Add(new Domino(4, 3));
            list.Add(new Domino(6, 2));
            list.Add(new Domino(2, 1));
            list.Add(new Domino(3, 2));
            Console.Write("|");
            list.Add(new Domino(6, 4));
            foreach (var e in list)
                Console.Write(e.firstDots + " " + e.secondDots + " | ");
            var start = list[rnd.Next(list.Count - 1)];
            var queue = new List<Domino>();
            queue.Add(start);
            var p = Play(list, queue, start);
            Console.WriteLine("\n\nРезультат игры:\n");
            Console.Write("|");
            foreach (var e in p)
                Console.Write(e.firstDots + " " + e.secondDots + " | ");
            Console.ReadKey();
        }

        public static List<Domino> Play(List<Domino> dominos, List<Domino> queue, Domino start)
        {
            dominos.Remove(start);
            for (int i = 0; i < dominos.Count; i++)
            {
                if (start.secondDots == dominos[i].firstDots)
                {
                    queue.Add(dominos[i]);
                    start = dominos[i];
                    Play(dominos, queue, start);
                }
                else if (start.secondDots == dominos[i].secondDots)
                {
                    var t = dominos[i].secondDots;
                    dominos[i].secondDots = dominos[i].firstDots;
                    dominos[i].firstDots = t;
                    queue.Add(dominos[i]);
                    start = dominos[i];
                    Play(dominos, queue, start);
                }
            }
            return queue;
        }
    }

    public class Domino
    {
        public int firstDots;
        public int secondDots;
        public Domino(int FirstDots, int SecondDots)
        {
            this.firstDots = FirstDots;
            this.secondDots = SecondDots;
        }
    }
}