using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var cityA = new City(new Location(0, 0));

        var cityB = new City(new Location(1, 1));

        var cityC = new City(new Location(2, 1));

        var cityD = new City(new Location(3, 1));

        var cityE = new City(new Location(4, 2));

        var cityF = new City(new Location(5, 3));

        cityA.AddConnection(cityB);

        cityB.AddConnection(cityC);

        cityB.AddConnection(cityE);

        cityC.AddConnection(cityD);

        cityC.AddConnection(cityE);

        cityE.AddConnection(cityF);

        var path = cityA.GetPathTo(cityF);

        Console.WriteLine("Path: " + path.GetReadableString());

        Console.WriteLine("Distance: " + path.CalculateDistance());

    }

}

​

class City

{

    public Location Location { get; private set; }

    public List<City> Connections { get; private set; }

​

    public City(Location location)

    {

        Location = location;

        Connections = new List<City>();

    }

​

    public void AddConnection(City city)

    {

        if (!Connections.Contains(city))

            Connections.Add(city);

​

        if (!city.Connections.Contains(this))

            city.AddConnection(this);

    }

​

    public Path GetPathTo(City city)

    {

        if (this == city)

            return new Path();

        var visitedCities = new List<City>();

        var citiesBuffer = new Queue<City>();

        var path = new Path();

​

        citiesBuffer.Enqueue(this);

        while (citiesBuffer.TryDequeue(out City picked))

        {

            path.Add(picked);

​

            if (picked.Connections.FirstOrDefault(x => x == city) != null)

            {

                path.Add(city);

                return path;

            }

​

            visitedCities.Add(picked);

​

            foreach (var notVisitedCity in picked.Connections.Where(x => !visitedCities.Contains(x)))

                citiesBuffer.Enqueue(notVisitedCity);

        }

​

        return new Path();

    }

}

​

class Location

{

    public int X { get; private set; }

    public int Y { get; private set; }

​

    public Location(int x, int y)

    {

        X = x;

        Y = y;

    }

​

    public double DistanceTo(Location location)

    {

        return Math.Sqrt(Math.Pow((location.X - X), 2) + Math.Pow((location.Y - Y), 2));

    }

}

​

class Path

{

    public List<City> Cities { get; private set; }

​

    public Path()

    {

        Cities = new List<City>();

    }

​

    public void Add(City city)

    {

        Cities.Add(city);

    }

​

    public double CalculateDistance()

    {

        var sum = 0d;

        var citiesArray = Cities.ToArray();

​

        for (int i = 0; i < citiesArray.Length - 1; i++)

        {

            sum += citiesArray[i].Location.DistanceTo(citiesArray[i+1].Location);

        }

​

        return sum;

    }

​

    public string GetReadableString()

    {

        var buffer = "";

        var citiesArray = Cities.ToArray();

​

        for (int i = 0; i < citiesArray.Length; i++)

        {

            buffer += $"[{citiesArray[i].Location.X},{citiesArray[i].Location.X}]";

​

            if (i < citiesArray.Length - 1)

                buffer += " => ";

        }

​

        return buffer;

    }

}

​