public static ChessMove GetBestMove(ChessBoard board, int depth, Progress progress)
{
Evaluator e = new Evaluator();
EvaluatedMove root = new EvaluatedMove(null, board);
e.Minimax(root, depth, progress);
EvaluatedMove[] bestMoves = root.Next.Where(m => (m != null) && (m.BestNextMoveValue == root.BestNextMoveValue)).ToArray();
IOrderedEnumerable<EvaluatedMove> orderedMoves = bestMoves.OrderBy(m => m.MateDepth); //.ThenBy(m => board[m.Move.Source]);
if (board.IsBlacksTurn)
orderedMoves = orderedMoves.ThenBy(m=>m.AccumulatedMoveValues);
else
orderedMoves = orderedMoves.ThenByDescending(m => m.AccumulatedMoveValues);
EvaluatedMove[] bestOrderedMoves = orderedMoves.ToArray();
if (random == null) random = new Random();
int moveIndex = -1;
for (int i = 1; i < bestOrderedMoves.Length; i++ )
{
if ((bestOrderedMoves[i].AccumulatedMoveValues != bestOrderedMoves[i - 1].AccumulatedMoveValues)
/*|| (board[bestOrderedMoves[i].Move.Source] != board[bestOrderedMoves[i - 1].Move.Source])*/
|| (bestOrderedMoves[i].MateDepth != bestOrderedMoves[i-1].MateDepth))
{
moveIndex = random.Next(i);
break;
}
}
if (moveIndex < 0)
moveIndex = random.Next(bestOrderedMoves.Length);
return bestOrderedMoves[moveIndex].Move;
}
public void CopyFrom(ChessBoard source)
{
for (int row = 0; row < 8; row++)
for (int col = 0; col < 8; col++)
{
board[row, col] = source.board[row, col];
}
flags = source.flags;
pawnJumpCol = source.pawnJumpCol;
}
public ChessBoard Clone()
{
ChessBoard clone = new ChessBoard();
clone.CopyFrom(this);
return clone;
}
/* Capitals are white pieces, and lowercase are black pieces.
* Initial layout looks like:
* rnbqkbnr
* pppppppp
*
*
*
*
* PPPPPPPP
* RNBQKBNR
*/
public static ChessBoard Parse(string boardString)
{
int stringPos = 0;
ChessBoard result = new ChessBoard();
for (int row = 0; row < 8; row++)
{
for (int col = 0; col < 8; col++)
{
if (stringPos >= boardString.Length)
throw new ArgumentException(string.Format("Expected row {0}, column {1} at string index {2}, but found end of string.", row, col, stringPos));
if (boardString[stringPos] == '\n')
{
col = 7;
continue;
}
else
result.board[row, col] = GetChessPiece(boardString[stringPos++]);
}
if ((stringPos < boardString.Length) && (boardString[stringPos++] != '\n'))
throw new ArgumentException(string.Format("Expected row {0} to be terminated by a newline", row));
}
return result;
}
public static ChessBoard FromUniqueKey(string key)
{
int index = 0;
int row = 0, col = 0;
ChessBoard result = new ChessBoard();
while ((index < key.Length) && (key[index] != '-'))
{
int distance = uniqueKeyDistanceCodes.IndexOf(key[index]);
if (distance >= 0)
{
int newCoord = row * 8 + col + distance + 1;
row = newCoord / 8;
col = newCoord % 8;
index++;
}
if (row >= 8)
throw new ArgumentException("Invalid board code");
result.board[row, col] = GetChessPiece(key[index++]);
col++;
if (col > 7)
{
col = 0;
row++;
}
}
if (index >= key.Length - 1)
throw new ArgumentException("Invalid board code");
result.flags = (BoardFlags)uniqueKeyDistanceCodes.IndexOf(key[++index]);
result.CheckForCheck();
return result;
}
public EvaluatedMove(ChessMove move, ChessBoard resultingState, EvaluatedMove predecessor = null)
{
this.move = move;
this.resultingState = resultingState;
this.Previous = predecessor;
}
public EvaluatedMove(ChessMove move, ChessBoard resultingState, EvaluatedMove predecessor = null)
{
this.move = move;
this.resultingState = resultingState;
this.Previous = predecessor;
}