public static GridPoint MoveRobot(
GridPoint initialPoint,
RobotDirection robotDirection)
{
if (RobotDirection.Left.Equals(robotDirection))
{
return(initialPoint.MoveLeft(1));
}
else if (RobotDirection.Right.Equals(robotDirection))
{
return(initialPoint.MoveRight(1));
}
else if (RobotDirection.Up.Equals(robotDirection))
{
return(initialPoint.MoveUp(1));
}
else if (RobotDirection.Down.Equals(robotDirection))
{
return(initialPoint.MoveDown(1));
}
else
{
throw new Exception($"Invalid robot direction {robotDirection}");
}
}
public static GridPoint GetNextPoint(
GridPoint robotPosition,
int movementCommand)
{
// Only four movement commands are understood: north (1),
// south (2), west (3), and east (4). Any other command is invalid.
// The movements differ in direction, but not in distance: in a
// long enough east-west hallway, a series of commands like
// 4,4,4,4,3,3,3,3 would leave the repair droid back where it
// started.
if (movementCommand == 1)
{
return(robotPosition.MoveUp(1));
}
else if (movementCommand == 2)
{
return(robotPosition.MoveDown(1));
}
else if (movementCommand == 3)
{
return(robotPosition.MoveLeft(1));
}
else if (movementCommand == 4)
{
return(robotPosition.MoveRight(1));
}
else
{
throw new Exception($"Invalid movement command {movementCommand}");
}
}
public static IList <GridPoint> GetAdjacentPoints(GridPoint point)
{
var result = new List <GridPoint>()
{
point.MoveLeft(1),
point.MoveRight(1),
point.MoveUp(1),
point.MoveDown(1)
};
return(result);
}
public static GridPoint[] GeneratePath(string[] instructions)
{
// Initialize the path with the origin
var currentPoint = new GridPoint();
var path = new List <GridPoint>(new GridPoint[] { currentPoint });
// Generate the path by reading each instruction and moving the
// current point to the next point as instructed
foreach (var rawInstruction in instructions)
{
// The instruction should be of the following pattern:
// 1) L/R/U/D for the direction
// 2) A number indicating how far to move
var instruction = rawInstruction.Trim();
var match = Regex.Match(instruction, "^(L|R|U|D)([0-9]+)$");
if (!match.Success)
{
throw new Exception($"Invalid instruction: {instruction}");
}
var direction = match.Groups[1].Value;
var distance = int.Parse(match.Groups[2].Value);
for (int i = 0; i < distance; i++)
{
if ("L".Equals(direction))
{
currentPoint = currentPoint.MoveLeft(1);
}
else if ("R".Equals(direction))
{
currentPoint = currentPoint.MoveRight(1);
}
else if ("U".Equals(direction))
{
currentPoint = currentPoint.MoveUp(1);
}
else if ("D".Equals(direction))
{
currentPoint = currentPoint.MoveDown(1);
}
path.Add(currentPoint);
}
}
return(path.ToArray());
}
public IList <GridPoint> GetPointNeighbors(
GridPoint point,
SortedDictionary <string, string> keysCollected,
GridPoint specificNeighborToAllow = null,
bool ignoreDoors = false)
{
var neighbors = new List <GridPoint>();
var candidates = new List <GridPoint>()
{
point.MoveLeft(1),
point.MoveRight(1),
point.MoveUp(1),
point.MoveDown(1)
};
foreach (var candidate in candidates)
{
if (!MazeCells.ContainsKey(candidate))
{
continue;
}
var candidateCell = MazeCells[candidate];
bool checkIfCanCenterCell = !(
specificNeighborToAllow != null &&
specificNeighborToAllow.Equals(candidate));
if (checkIfCanCenterCell)
{
if (!GetCanEnterCell(candidate, keysCollected, ignoreDoors))
{
continue;
}
}
neighbors.Add(candidate);
}
return(neighbors);
}