protected virtual void DoWalk(RouteStep routeStep)
{
var currentCoordinates = new RoutePoint(XCoordinate, YCoordinate);
switch (_direction)
{
case Direction.Up:
YCoordinate += routeStep.Distance;
break;
case Direction.Down:
YCoordinate -= routeStep.Distance;
break;
case Direction.Left:
XCoordinate -= routeStep.Distance;
break;
case Direction.Right:
XCoordinate += routeStep.Distance;
break;
default:
throw new ArgumentOutOfRangeException();
}
var newCoordinates = new RoutePoint(XCoordinate, YCoordinate);
Links.Add(new RouteLink(currentCoordinates, newCoordinates));
}
public RouteLink(RoutePoint start, RoutePoint finish)
{
if (start.X != finish.X && start.Y != finish.Y)
{
throw new ArgumentException("Must be strictly horizontal or vertical link.");
}
if (start.Equals(finish))
{
throw new ArgumentException("Must not be same points.");
}
Start = start;
Finish = finish;
}
public static void Main(string[] args)
{
Console.WriteLine("Advent Of Code 2016, day 1");
var input = InputUtils.GetInput(args).ReadToEnd();
var routeParser = new RouteParser();
var steps = routeParser.GetSteps(input).ToArray();
var walker = new RouteWalker();
walker.Walk(steps);
var totalDistance = Math.Abs(walker.XCoordinate) + Math.Abs(walker.YCoordinate);
Console.WriteLine($"Answer to question 1: {totalDistance}");
RoutePoint intersection = null;
for (int i = 4; i <= walker.Links.Count; i++)
{
var subList = walker.Links.Take(i).ToList();
var subject = subList.Last();
foreach (var routeLink in subList.AsEnumerable().Reverse().Skip(3))
{
intersection = subject.FindIntersection(routeLink);
if (intersection != null)
{
break;
}
}
if (intersection != null)
{
break;
}
}
if (intersection != null)
{
var intersectionDistance = Math.Abs(intersection.X) + Math.Abs(intersection.Y);
Console.WriteLine($"Answer to question 2: {intersectionDistance}");
}
}