public int FirstVisitedDistance(string input)
{
HashSet <Location> visits = new HashSet <Location>();
var instructions = input.Split(',')
.Select(x =>
{
var instruction = x.Trim();
return(new Vector
{
Direction = instruction.Substring(0, 1) == "R" ? 90 : -90,
Magnitude = Convert.ToInt32(instruction.Substring(1))
});
});
CurrentCompassBearing = CompassBearing.North;
CurrentLocation = new Location(0, 0);
foreach (var vector in instructions)
{
SetNewDirection(vector.Direction);
var found = UpdateLocationWithTracking(visits, vector.Magnitude);
if (found)
{
break;
}
}
return(Math.Abs(CurrentLocation.X) + Math.Abs(CurrentLocation.Y));
}
public void SetNewDirection(int turn)
{
var newBearing = (Convert.ToInt32(CurrentCompassBearing) + turn);
if (newBearing < 0)
{
newBearing += 360;
}
CurrentCompassBearing = (CompassBearing)(newBearing % 360);
}
private string GetNextPath(CompassBearing bearing)
{
switch (bearing)
{
case CompassBearing.North: return("U");
case CompassBearing.East: return("R");
case CompassBearing.South: return("D");
case CompassBearing.West: return("L");
}
throw new Exception("Invalid enum passed in");
}
public Day17MazeState(Day17MazeState state, CompassBearing direction)
{
Path = state.Path;
Location = new Location(state.Location.X, state.Location.Y);
Path = state.Path + GetNextPath(direction);
if (direction == CompassBearing.North)
{
Location.Y--;
}
else if (direction == CompassBearing.East)
{
Location.X++;
}
else if (direction == CompassBearing.South)
{
Location.Y++;
}
else if (direction == CompassBearing.West)
{
Location.X--;
}
}
