public virtual int GetDistanceOfShortestRoute(List<Track> railRoad, City origin, City destination)
{
var possibleRoutes = FindAllPossibleRoutes(railRoad, origin, destination);
if (possibleRoutes.Count() == 0)
throw new NoRouteException();
return possibleRoutes.OrderBy(x => x.DistanceFromStart).First(x => x.DistanceFromStart != 0).DistanceFromStart;
}
protected List<RouteWithDistanceFromStart> FindAllPossibleRoutes(List<Track> railRoad, City origin, City finalDestination)
{
if (RailRoadHasNoTracks(railRoad))
throw new NoRouteException();
FinalDestination = finalDestination;
possibleRoutes = new List<RouteWithDistanceFromStart>();
var initialRoute = StartRoute(origin);
FindAllPossibleRoutes(railRoad, origin, initialRoute);
return possibleRoutes;
}
public virtual int GetNumberOfRoutesWithDistanceLimit(List<Track> railRoad, City origin, City destination, int distanceLimit)
{
this.distanceLimit = distanceLimit;
var possibleRoutes = FindAllPossibleRoutes(railRoad, origin, destination);
if (possibleRoutes.Count() == 0)
throw new NoRouteException();
return possibleRoutes.Where(x => x.DistanceFromStart < distanceLimit).Count();
}
protected virtual int FindNumberOfPossibleRoutes(List<Track> railRoad, City origin, City finalDestination)
{
if (RailRoadHasNoTracks(railRoad))
throw new NoRouteException();
possibleRoutesCounter = 0;
FinalDestination = finalDestination;
var initialRoute = StartRoute(origin);
FindNumberOfPossibleRoutes(railRoad, origin, initialRoute);
return possibleRoutesCounter;
}
public void ShouldIdentifyIfTheTrackConnectTheGivenCities()
{
var origin = new City("A");
var destination = new City("B");
var otherCity = new City("C");
var track = new Track(origin, destination, 4);
track.IsAConnectionBetween(origin, destination).Should().BeTrue();
track.IsAConnectionBetween(origin, otherCity).Should().BeFalse();
}
public static Track Parse(string track)
{
try
{
var origin = new City(track[0].ToString());
var destination = new City(track[1].ToString());
var distance = Convert.ToInt32(track.Substring(2, track.Length - 2));
return new Track(origin, destination, distance);
}
catch (Exception e)
{
throw new FormatException("The input route is incorrect.", e);
}
}
private void FindAllPossibleRoutes(List<Track> railRoad, City origin, RouteWithDistanceFromStart runningRoute)
{
var possibleTracks = railRoad.FindAll(track => track.Origin.Equals(origin));
foreach (var track in possibleTracks)
{
var route = (RouteWithDistanceFromStart)runningRoute.Clone();
route.AppendCity(track.Destination, track.Distance);
if (ThisTrackWillLeadMeToDestination(track))
possibleRoutes.Add(route);
if (ShouldKeepRunningInThisRoute(runningRoute, track))
FindAllPossibleRoutes(railRoad, track.Destination, route);
}
}
private void FindNumberOfPossibleRoutes(List<Track> railRoad, City origin, Route runningRoute)
{
var possibleTracks = railRoad.FindAll(track => track.Origin.Equals(origin));
foreach (var track in possibleTracks)
{
var route = (Route)runningRoute.Clone();
route.AppendCity(track.Destination);
if (ThisRouteMatchWithTheRequisites(route))
possibleRoutesCounter++;
if (ShouldKeepRunningInThisRoute(route))
FindNumberOfPossibleRoutes(railRoad, track.Destination, route);
}
}
public void Should_Find_Number_Of_Routes_With_Limited_Distances_On_A_Simple_RailRoad()
{
var A = new City("A");
var B = new City("B");
var railRoad = new List<Track>();
railRoad.Add(new Track(A, B, 5));
railRoad.Add(new Track(A, B, 8));
railRoad.Add(new Track(A, B, 2));
railRoad.Add(new Track(A, B, 50));
railRoad.Add(new Track(A, B, 21));
railRoad.Add(new Track(A, B, 1));
railRoad.Add(new Track(A, B, 17));
railRoad.Add(new Track(A, B, 6));
routesFinder.GetNumberOfRoutesWithDistanceLimit(railRoad, A, B, 6).Should().Be(3);
}
public Track(City origin, City destination, int distance)
{
Origin = origin;
Destination = destination;
Distance = distance;
}
public bool IsAConnectionBetween(City origin, City destination)
{
return Origin.Equals(origin) && Destination.Equals(destination);
}
private void EvaluateOriginAndDestination(Route route)
{
currentCity = route.Cities.Peek();
route.Cities.Dequeue();
nextCity = route.Cities.Peek();
}
public virtual int Find(List<Track> railroad, City origin, City finaldestination, int maxStops)
{
maximumStops = maxStops;
return FindNumberOfPossibleRoutes(railroad, origin, finaldestination);
}
private static RouteWithDistanceFromStart StartRoute(City origin)
{
var initialRoute = new RouteWithDistanceFromStart();
initialRoute.AppendCity(origin, 0);
return initialRoute;
}
private static Route StartRoute(City origin)
{
var initialRoute = new Route();
initialRoute.AppendCity(origin);
return initialRoute;
}
public virtual int FindPossibleRoutes(List<Track> railRoad, City origin, City finalDestionation, int exactNumberOfStops)
{
exactNumberOfStopsExpected = exactNumberOfStops;
return FindNumberOfPossibleRoutes(railRoad, origin, finalDestionation);
}
public void Should_Return_Zero_Routes_If_The_Origin_Is_A_Leaf()
{
var railRoad = GivenA.SimpleRailRoad();
var leaf = new City("Z");
routeFinder.FindPossibleRoutes(railRoad, leaf, new City("A"), 1).Should().Be(0);
}
public void AppendCity(City city, int distance)
{
DistanceFromStart += distance;
Cities.Enqueue(city);
}