private static bool DoDepthFirstSearchingAux(Dictionary<string, int> existingRoutes, ref MaxTripsResult runningResult, string fromToKey, string requestedRoute, ref int runningStops, int maxStops)
{
// Concept: the minute you have entered this function, you have gone from...to. (See fromToKey.) So update recordkeeping now.
UpdateRunningStops(ref runningStops);
if (!CheckIfMaxStopsExceeded(runningStops, maxStops)) return false;
runningResult.Legs.Add(new Trip{Leg = fromToKey, Distance = existingRoutes[fromToKey]});
var requestedDest = requestedRoute[1];
var currentDest = fromToKey[1];
if (YouHaveReachedYourDestination(requestedDest, currentDest))
return true;
var nextLocation = currentDest;
var possibleRoutes = existingRoutes.Where(r => r.Key[0] == nextLocation);
if (!possibleRoutes.Any())
return false;
foreach (var route in possibleRoutes)
{
var savedRunningResult = runningResult;
if (DoDepthFirstSearchingAux(existingRoutes, ref savedRunningResult, route.Key, requestedRoute, ref runningStops, maxStops))
{
return true;
}
runningResult = savedRunningResult;
}
return false;
}
private static List<MaxTripsResult> DoDepthFirstSearching(Dictionary<string, int> availableRoutes, string requestedRoute, int maxStops)
{
var results = new List<MaxTripsResult>();
var possibleLegs = availableRoutes.Where(r => r.Key[0] == requestedRoute[0]);
foreach (var legs in possibleLegs)
{
var tempResult = new MaxTripsResult {Legs = new List<Trip>()};
var runningStops = 0;
if (DoDepthFirstSearchingAux(availableRoutes, ref tempResult, legs.Key, requestedRoute, ref runningStops, maxStops))
{
results.Add(tempResult);
};
}
return results;
}
public void OneTripReturnedLessThanMaxStops()
{
var requestedTrip = "AD";
var exactStops = 2;
var threeStopTrip = new List<Trip>{new Trip(), new Trip(), new Trip(), new Trip()};
var maxTripsResult = new MaxTripsResult{Legs = threeStopTrip};
var oneTripReturned = new List<MaxTripsResult>
{
maxTripsResult,
};
_maxTripsCalculator.Expect(
mtc =>
mtc.Invoke(Arg<Dictionary<string, int>>.Is.Anything, Arg<string>.Is.Anything,
Arg<int>.Is.Anything)).Return(oneTripReturned);
var numTrips = _calcer.Invoke(_possibleLegs, requestedTrip, exactStops);
Assert.That(numTrips, Is.EqualTo(0));
}
private static bool ResultMatchesRequestedStops(int exactStops, MaxTripsResult result)
{
return result.Legs.Count - 1 == exactStops;
}
