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;
}
private void Minimax(EvaluatedMove predecessor, int depth, Progress progress)
{
if ((depth == 0) || (predecessor.ResultingState.BoardValue == -9999) || (predecessor.ResultingState.BoardValue == 9999))
{
predecessor.BestNextMoveValue = predecessor.ResultingState.BoardValue;
return;
}
ChessMove[] moves = predecessor.ResultingState.GetValidMoves().ToArray();
predecessor.Next = new EvaluatedMove[moves.Length];
if (predecessor.ResultingState.IsBlacksTurn)
{
predecessor.BestNextMoveValue = 9999;
for (int i = 0; i < moves.Length; i++)
{
if (progress != null)
progress(i + 1, moves.Length);
predecessor.Next[i] = new EvaluatedMove(moves[i], predecessor.ResultingState.Move(moves[i]), predecessor);
Minimax(predecessor.Next[i], depth - 1, null);
predecessor.AccumulatedMoveValues += predecessor.ResultingState.BoardValue + predecessor.Next[i].AccumulatedMoveValues;
if (predecessor.Next[i].BestNextMoveValue < predecessor.BestNextMoveValue)
predecessor.BestNextMoveValue = predecessor.Next[i].BestNextMoveValue;
if ((predecessor.BestNextMoveValue == -9999) && (predecessor.Next[i].MateDepth == 0))
predecessor.Next[i].MateDepth = 1;
if (predecessor.Next[i].MateDepth > 0)
predecessor.MateDepth = (byte)(predecessor.Next[i].MateDepth + 1);
}
}
else
{
predecessor.BestNextMoveValue = -9999;
for (int i = 0; i < moves.Length; i++)
{
if (progress != null)
progress(i + 1, moves.Length);
predecessor.Next[i] = new EvaluatedMove(moves[i], predecessor.ResultingState.Move(moves[i]), predecessor);
Minimax(predecessor.Next[i], depth - 1, null);
predecessor.AccumulatedMoveValues += predecessor.ResultingState.BoardValue + predecessor.Next[i].AccumulatedMoveValues;
if (predecessor.Next[i].BestNextMoveValue > predecessor.BestNextMoveValue)
predecessor.BestNextMoveValue = predecessor.Next[i].BestNextMoveValue;
if ((predecessor.BestNextMoveValue == 9999) && (predecessor.Next[i].MateDepth == 0))
predecessor.Next[i].MateDepth = 1;
if (predecessor.Next[i].MateDepth > 0)
predecessor.MateDepth = (byte)(predecessor.Next[i].MateDepth + 1);
}
}
}
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);
}
private void Minimax(EvaluatedMove predecessor, int depth, Progress progress)
{
if ((depth == 0) || (predecessor.ResultingState.BoardValue == -9999) || (predecessor.ResultingState.BoardValue == 9999))
{
predecessor.BestNextMoveValue = predecessor.ResultingState.BoardValue;
return;
}
ChessMove[] moves = predecessor.ResultingState.GetValidMoves().ToArray();
predecessor.Next = new EvaluatedMove[moves.Length];
if (predecessor.ResultingState.IsBlacksTurn)
{
predecessor.BestNextMoveValue = 9999;
for (int i = 0; i < moves.Length; i++)
{
if (progress != null)
{
progress(i + 1, moves.Length);
}
predecessor.Next[i] = new EvaluatedMove(moves[i], predecessor.ResultingState.Move(moves[i]), predecessor);
Minimax(predecessor.Next[i], depth - 1, null);
predecessor.AccumulatedMoveValues += predecessor.ResultingState.BoardValue + predecessor.Next[i].AccumulatedMoveValues;
if (predecessor.Next[i].BestNextMoveValue < predecessor.BestNextMoveValue)
{
predecessor.BestNextMoveValue = predecessor.Next[i].BestNextMoveValue;
}
if ((predecessor.BestNextMoveValue == -9999) && (predecessor.Next[i].MateDepth == 0))
{
predecessor.Next[i].MateDepth = 1;
}
if (predecessor.Next[i].MateDepth > 0)
{
predecessor.MateDepth = (byte)(predecessor.Next[i].MateDepth + 1);
}
}
}
else
{
predecessor.BestNextMoveValue = -9999;
for (int i = 0; i < moves.Length; i++)
{
if (progress != null)
{
progress(i + 1, moves.Length);
}
predecessor.Next[i] = new EvaluatedMove(moves[i], predecessor.ResultingState.Move(moves[i]), predecessor);
Minimax(predecessor.Next[i], depth - 1, null);
predecessor.AccumulatedMoveValues += predecessor.ResultingState.BoardValue + predecessor.Next[i].AccumulatedMoveValues;
if (predecessor.Next[i].BestNextMoveValue > predecessor.BestNextMoveValue)
{
predecessor.BestNextMoveValue = predecessor.Next[i].BestNextMoveValue;
}
if ((predecessor.BestNextMoveValue == 9999) && (predecessor.Next[i].MateDepth == 0))
{
predecessor.Next[i].MateDepth = 1;
}
if (predecessor.Next[i].MateDepth > 0)
{
predecessor.MateDepth = (byte)(predecessor.Next[i].MateDepth + 1);
}
}
}
}
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;
}