Anyone know C# Code for Travelling Salesman problem?

using System; using System.Collections.Generic; using System.Linq; using System.Text;  namespace TSP {     static class Program     {   static void Main(string[] args)   {    //create an initial tour out of nearest neighbors    var stops = Enumerable.Range(1, 10)     .Select(i => new Stop(new City(i)))     .NearestNeighbors()     .ToList();     //create next pointers between them    stops.Connect(true);     //wrap in a tour object    Tour startingTour = new Tour(stops);     //the actual algorithm    while (true)    {     Console.WriteLine(startingTour);     var newTour = startingTour.GenerateMutations()      .MinBy(tour => tour.Cost());     if (newTour.Cost() < startingTour.Cost())      startingTour = newTour;     else break;    }     Console.ReadLine();   }    class City   {    private static Random rand = new Random();     public City(int cityName)    {     X = rand.NextDouble() * 100;     Y = rand.NextDouble() * 100;     CityName = cityName;    }     public double X { get; private set; }    public double Y { get; private set; }    public int CityName { get; private set; }   }    class Stop   {    public Stop(City city)    {     City = city;    }     public Stop Next { get; set; }    public City City { get; set; }     public Stop Clone()    {     return new Stop(City);    }     public static double Distance(Stop first, Stop other)    {     return Math.Sqrt(Math.Pow(first.City.X - other.City.X, 2) +       Math.Pow(first.City.Y - other.City.Y, 2));    }     //list of nodes, including this one, that we can get to    public IEnumerable<Stop> CanGetTo()    {     var current = this;     while (true)     {      yield return current;      current = current.Next;      if (current == this)       break;     }    }     public override bool Equals(object obj)    {     return City == ((Stop)obj).City;    }     public override int GetHashCode()    {     return City.GetHashCode();    }     public override string ToString()    {     return City.CityName.ToString();    }   }    class Tour   {    public Tour(IEnumerable<Stop> stops)    {     Anchor = stops.First();    }     //the set of tours we can make with 2-opt out of this one    public IEnumerable<Tour> GenerateMutations()    {     for (Stop stop = Anchor; stop.Next != Anchor; stop = stop.Next)     {      //skip the next one, since you can't swap with that      Stop current = stop.Next.Next;      while (current != Anchor)      {       yield return CloneWithSwap(stop.City, current.City);       current = current.Next;      }     }    }     public Stop Anchor { get; set; }     public Tour CloneWithSwap(City firstCity, City secondCity)    {     Stop firstFrom = null, secondFrom = null;     var stops = UnconnectedClones();     stops.Connect(true);      foreach (Stop stop in stops)     {      if (stop.City == firstCity)       firstFrom = stop;       if (stop.City == secondCity)       secondFrom = stop;     }      //the swap part     var firstTo = firstFrom.Next;     var secondTo = secondFrom.Next;      //reverse all of the links between the swaps     firstTo.CanGetTo()      .TakeWhile(stop => stop != secondTo)      .Reverse()      .Connect(false);      firstTo.Next = secondTo;     firstFrom.Next = secondFrom;      var tour = new Tour(stops);     return tour;    }     public IList<Stop> UnconnectedClones()    {     return Cycle().Select(stop => stop.Clone()).ToList();    }     public double Cost()    {     return Cycle().Aggregate(0.0, (sum, stop) =>       sum + Stop.Distance(stop, stop.Next));    }     private IEnumerable<Stop> Cycle()    {     return Anchor.CanGetTo();    }     public override string ToString()    {     string path = String.Join("->",       Cycle().Select(stop => stop.ToString()).ToArray());     return String.Format("Cost: {0}, Path:{1}", Cost(), path);    }    }    //take an ordered list of nodes and set their next properties   static void Connect(this IEnumerable<Stop> stops, bool loop)   {    Stop prev = null, first = null;    foreach (var stop in stops)    {     if (first == null)      first = stop;     if (prev != null)      prev.Next = stop;     prev = stop;    }     if (loop)    {     prev.Next = first;    }   }    //T with the smallest func(T)   static T MinBy<T, TComparable>(this IEnumerable<T> xs,                                                  Func<T, TComparable> func)     where TComparable : IComparable<TComparable>   {    return xs.DefaultIfEmpty().Aggregate((maxSoFar, elem) =>      func(elem).CompareTo(func(maxSoFar)) > 0 ? maxSoFar : elem);   }    //return an ordered nearest neighbor set   static IEnumerable<Stop> NearestNeighbors(this IEnumerable<Stop> stops)   {    var stopsLeft = stops.ToList();    for (var stop = stopsLeft.First();      stop != null;      stop = stopsLeft.MinBy(s => Stop.Distance(stop, s)))    {     stopsLeft.Remove(stop);     yield return stop;    }   }     } }