private void FloodFillMinDistancesQueen(Point point, PieceGrid pieceGrid, PointSquareArray <double?> result)
{
ISet <Point> visited = new HashSet <Point>();
Queue <(Point, double)> toVisit = new Queue <(Point, double)>();
foreach (Point p in pieceGrid.GetOpenPointsOutFrom(point))
{
toVisit.Enqueue((p, 1));
}
while (toVisit.Any())
{
(Point, double)p = toVisit.Dequeue();
if (visited.Contains(p.Item1))
{
continue;
}
if (result[p.Item1].HasValue)
{
result[p.Item1] = Math.Min(p.Item2, result[p.Item1].Value);
}
else
{
result.Add(p.Item1, p.Item2);
}
visited.Add(p.Item1);
foreach (Point pNext in pieceGrid.GetOpenPointsOutFrom(p.Item1)
.Where(adj => !visited.Contains(adj)))
{
toVisit.Enqueue((pNext, p.Item2 + 1));
}
}
}
/// <summary>
/// Calculate the mobility score for a specific amazon point on the PieceGrid.
/// </summary>
/// <remarks>
/// Mobility is based on the breathing space of each space that can be moved to by an
/// amazon at the given point. Closer (king distance) spaces are more valuable than
/// distant ones.
/// </remarks>
/// <param name="p">Point containing an amazon</param>
/// <param name="pieceGrid">PieceGrid to analyze</param>
/// <returns>Numeric mobility score, higher numbers = more mobile</returns>
private double CalculateAmazonMobility(Point p, Owner owner, PieceGrid pieceGrid)
{
IDictionary <Point, double?> minDistancesOppositePlayer;
if (owner == Owner.Player1)
{
minDistancesOppositePlayer = Player2QueenMinDistances;
}
else if (owner == Owner.Player2)
{
minDistancesOppositePlayer = Player1QueenMinDistances;
}
else
{
throw new ArgumentException($"Point {p} doesn't have an amazon for either player!");
}
double mobility = 0d;
foreach (Point target in pieceGrid.GetOpenPointsOutFrom(p))
{
int degree = target.GetAdjacentPoints()
.Where(adj => pieceGrid.PointPieces.ContainsKey(adj) && !pieceGrid.PointPieces[adj].Impassible)
.Count();
if (!minDistancesOppositePlayer.ContainsKey(target))
{
continue;
}
if (owner == Owner.Player1 && !LocalAdvantages[target].Player2Reachable)
{
continue;
}
if (owner == Owner.Player2 && !LocalAdvantages[target].Player1Reachable)
{
continue;
}
double localMobility = Math.Pow(2, -(SpecificKingDistances[p][target])) * degree;
mobility += localMobility;
}
return(mobility);
}