private Direction PickDifferentDirection(LinkedCell currentLocation, Direction directionToScaryGhost)
{
var possibleDirections = currentLocation.AvailableMoves.ToList();
var directionWeDontWantToTake = possibleDirections.Single(d => d.Direction == directionToScaryGhost);
possibleDirections.Remove(directionWeDontWantToTake);
return(possibleDirections.First().Direction);
}
private Direction AvoidGhost(LinkedCell currentLocation,
Distances shortestDistances, Direction bestDirectionToNearestCoin, BotGhost?nearestGhost)
{
if (nearestGhost is object)
{
var distanceToGhost = shortestDistances.DistanceTo(nearestGhost.Location);
if (distanceToGhost < 5)
{
var directionToScaryGhost = shortestDistances.DirectionToTarget(nearestGhost.Location);
if (directionToScaryGhost == bestDirectionToNearestCoin)
{
bestDirectionToNearestCoin = PickDifferentDirection(currentLocation, directionToScaryGhost);
}
}
}
return(bestDirectionToNearestCoin);
}
public static Distances CalculateDistances(BotGame game, Graph.Graph graph, LinkedCell currentLocation)
{
//1
var width = game.Board.Width;
var height = game.Board.Height;
var shortestDistances = new int[width, height];
var visited = new bool[width, height];
for (int r = 0; r < height; r++)
{
for (int c = 0; c < width; c++)
{
shortestDistances[c, r] = int.MaxValue;
}
}
//2
shortestDistances[currentLocation.Location.X, currentLocation.Location.Y] = 0;
visited[currentLocation.Location.X, currentLocation.Location.Y] = true;
//3
CellLocation?currentNode = currentLocation.Location;
while (currentNode is object)
{
var distanceToCurrentNode = shortestDistances[currentNode.Value.X, currentNode.Value.Y];
var linkedCell = graph.GetNodeForLocation(currentNode.Value);
foreach (var(_, newLocation) in linkedCell.AvailableMoves)
{
if (!visited[newLocation.Location.X, newLocation.Location.Y])
{
var tentativeDistance = distanceToCurrentNode + 1;
var currentValue = shortestDistances[newLocation.Location.X, newLocation.Location.Y];
shortestDistances[newLocation.Location.X, newLocation.Location.Y] = Math.Min(tentativeDistance, currentValue);
}
}
//4
visited[currentNode.Value.X, currentNode.Value.Y] = true;
var bestScore = int.MaxValue;
currentNode = null;
for (int r = 0; r < height; r++)
{
for (int c = 0; c < width; c++)
{
var seen = visited[c, r];
if (!seen)
{
if (shortestDistances[c, r] < bestScore)
{
bestScore = shortestDistances[c, r];
currentNode = new CellLocation(c, r);
}
}
}
}
}
return(new Distances(shortestDistances, graph));
}
