public static Path GetBestPath(Board b, Options o, BoardScorer.Options bso)
{
Path bestPath = new Path();
object pathLock = new object();
Parallel.For(0, b.Height, i =>
{
//for (int i = 0; i < b.Height; i++)
Parallel.For(0, b.Width, j =>
{
//for (int j = 0; j < b.Width; j++)
var curPath = GetBestPathFrom(b, o, i, j, bso);
lock (pathLock)
{
if (curPath.Score > bestPath.Score)
bestPath = curPath;
}
});
});
return bestPath;
}
private static Path GetBestPathFrom(Board b, Options o, int y, int x, BoardScorer.Options bso)
{
Path bestPath = new Path();
PriorityQueue<Tuple<Board, Path>, double> paths = new PriorityQueue<Tuple<Board, Path>, double>();
paths.Enqueue(new Tuple<Board, Path>(b, new Path
{
Start = new Tuple<int, int>(y, x),
Current = new Tuple<int, int>(y, x),
Depth = 1,
Score = b.Score(bso)
}));
int depth = 0;
while (depth++ < o.MaxDepth)
{
// Console.WriteLine("currently at depth {0}...", depth);
PriorityQueue<Tuple<Board, Path>, double> newPaths = new PriorityQueue<Tuple<Board, Path>, double>();
while (paths.Count != 0)
{
var cur = paths.Dequeue();
var curPath = cur.Item2;
var curBoard = cur.Item1;
if (curPath.Score > bestPath.Score)
bestPath = curPath;
//if (paths.Count() > o.WhenToPrune)
//{
// var newPaths = new Stack<Tuple<Board, Path>>();
// foreach (var path in paths.OrderByDescending(p => p.Item2.Score).Take(o.NumToKeep).Reverse())
// newPaths.Push(path);
// paths = newPaths;
//}
foreach (var direction in Board.MoveDirections)
{
if (curPath.Length != 0 &&
curPath.Actions.Last()[0] == -direction[0] &&
curPath.Actions.Last()[1] == -direction[1])
continue;
var newY = curPath.Current.Item1 + direction[0];
var newX = curPath.Current.Item2 + direction[1];
if (newY < 0 || newY >= b.Height ||
newX < 0 || newX >= b.Width)
continue;
Board newBoard = new Board(curBoard);
Orb tempOrb = newBoard.Orbs[newY, newX];
newBoard.Orbs[newY, newX] = newBoard.Orbs[curPath.Current.Item1, curPath.Current.Item2];
newBoard.Orbs[curPath.Current.Item1, curPath.Current.Item2] = tempOrb;
var newPath = new List<int[]>(curPath.Actions);
newPath.Add(direction);
double score = newBoard.Score(bso) - curPath.Depth / 100;
newPaths.Enqueue(new Tuple<Board, Path>(newBoard, new Path
{
Start = curPath.Start,
Current = new Tuple<int, int>(newY, newX),
Depth = curPath.Depth + 1,
Score = score,
Actions = newPath
}), score);
}
}
paths = newPaths.TrimToSize(o.BeamWidth);
}
return bestPath;
}
public static Path GetBestPath(Board b, BoardScorer.Options bso)
{
return GetBestPath(b, Options.Default, bso);
}
