int AlphaBeta(int depth, int alpha, int beta)
{
int score = 0;
int ttMove = 0;
int bestMove = 0;
TTType ttFlag = TTType.Alpha;
if (clk.GetElapsedMilliseconds() > totalMillisec)
{
return(0); // timeout
}
if (depth == 0)
{
return(Quiesce(alpha, beta, 0));
}
else
{
if (ttable.Probe(board.ZKey, depth, alpha, beta, ref ttMove, ref score))
{
return(score);
}
bestMove = ttMove;
var moves = GetMoves(bestMove, depth);
if (moves.Count() == 0)
{
score = board.InCheck(board.ToMove)?-INFINITE:0;
ttable.Save(board.ZKey, depth, score, TTType.Exact, 0);
return(score);
}
foreach (var move in moves)
{
board.Move(move);
score = -AlphaBeta(depth - 1, -beta, -alpha);
board.UndoMove();
if (score > alpha)
{
bestMove = move;
alpha = score;
ttFlag = TTType.Exact;
}
if (alpha >= beta) // current plaier move is better than the other one better, no reason to search further
{
//beta cutoff !!!
ttable.Save(board.ZKey, depth, beta, TTType.Beta, bestMove);
if (0 != (MovePackHelper.Capture & move))
{
StoreKiller(depth, move);
}
return(beta);
}
}
ttable.Save(board.ZKey, depth, alpha, ttFlag, bestMove);
return(alpha);
}
}
public int Search(IChessBoard board, int alpha, int beta, int depth)
{
if (depth == 0)
{
return(quiesce(board, alpha, beta));
}
else
{
var moves = getMoves(board);
if (moves.Count() == 0)
{
return(zeroMoveEval());
}
foreach (var move in moves)
{
board.Move(move);
var score = -Search(board, -beta, -alpha, depth - 1);
board.UndoMove();
if (score > alpha)
{
foundMove(board, move, depth, score);
alpha = score;
}
if (alpha >= beta) // current plaier move is better than the other one better, no reason to search further
{
//beta cutoff !!!
betaCutoff(board, move, depth, score);
break;
}
}
return(alpha);
}
}
protected override int DoSearch(IChessBoard board, TimeSpan timeAvail)
{
this.totalMillisec = (int)timeAvail.TotalMilliseconds;
this.board = board;
int bestMove = 0;
int val = 0;
int alpha;
bool timeout = false;
kslot = new long[200];
using (clk = new RunClock())
{
var preOrder = GetPreOrderedMoves();
for (int curDepth = 1; curDepth <= maxDepth; ++curDepth) // iterative deeping
{
alpha = -INFINITE;
var moves = GetBestMoveFirst(bestMove, preOrder);
//var moves = GetMoves(bestMove);
foreach (var m in moves)
{
board.Move(m);
var cm = MovePackHelper.GetAlgebraicString(m);
if (m == bestMove || -AlphaBeta(curDepth - 1, -alpha - 1, -alpha) > alpha)
{
val = -AlphaBeta(curDepth - 1, -INFINITE, -alpha);
}
board.UndoMove();
if (val > alpha)
{
alpha = val;
bestMove = m;
ttable.Save(board.ZKey, curDepth, alpha, TTType.Alpha, m);
}
if (clk.GetElapsedMilliseconds() > timeAvail.TotalMilliseconds / .5)
{
timeout = true;
break;
}
}
if (timeout)
{
break;
}
ttable.Save(board.ZKey, curDepth, alpha, TTType.Alpha, bestMove);
}
}
return(bestMove);
}
public static string ProduceShortAlgebraicString(IChessBoard board, int p)
{
board.TestInCheck(board.ToMove);
int [] moves = new int[200];
board.GetMoves(0, moves);
List <int> possibles = new List <int>();
int end = MovePackHelper.GetEndSquare(p);
foreach (var m in moves)
{
if (GetEndSquare(m) == end && board.BoardArray[GetStartSquare(m)].Type == board.BoardArray[GetStartSquare(p)].Type)
{
possibles.Add(p);
}
}
StringBuilder sb = new StringBuilder();
var spiece = board.BoardArray[GetStartSquare(p)];
if (spiece.Type != PieceType.Pawn)
{
sb.Append(spiece.ToString().ToUpper());
}
if (possibles.Count > 1)
{
var squares = possibles.Select(k => GetSquareString(GetStartSquare(k)));
if (squares.Select(k => k[0]).Distinct().Count() > 1)
{
sb.Append(GetSquareString(GetStartSquare(p))[0]);
}
else if (squares.Select(k => k[1]).Distinct().Count() > 1)
{
sb.Append(GetSquareString(GetStartSquare(p))[1]);
}
else
{
sb.Append(GetSquareString(GetStartSquare(p)));
}
}
if (HasCapture(p))
{
sb.Append("x");
}
sb.Append(GetSquareString(GetEndSquare(p)));
board.Move(p);
board.TestInCheck(board.ToMove);
int cnt = board.GetCheckCount(board.ToMove);
if (cnt > 0)
{
int[] tmp = new int[200];
if (0 == board.GetMoves(0, tmp))
{
sb.Append("#");
}
else
{
sb.Append(new string('+', cnt));
}
}
board.UndoMove();
return(sb.ToString());
}
public void Consume(string input)
{
string[] tokens = input.Split(' ');
string rPart = "";
for (int i = 1; i < tokens.Length; ++i)
{
rPart += tokens[i];
rPart += " ";
}
rPart = rPart.Trim();
if (!edit)
{
switch (tokens[0])
{
//Ignore unhandled commands
case "level":
case "otim":
case "time":
case "random":
case "hard":
case "easy":
case "sd":
case "st":
case "strong":
case "post":
case "result":
case "computer":
case "?":
break;
case "savepos":
OnMessageToWinboard(board.SavePos());
break;
case "divide":
int depth = int.Parse(rPart);
board.DividePartialResult += new EventHandler(div_DividePartialResult);
DivideResults div = board.Divide(depth);
OnMessageToWinboard(string.Format("Total Nodes: {0}", div.NodesCount));
OnMessageToWinboard(string.Format("Moves Count: {0}", div.MovesCount));
board.DividePartialResult -= new EventHandler(div_DividePartialResult);
break;
case "qperft":
OnMessageToWinboard("Performing perft with hash table");
depth = int.Parse(rPart);
PerfResults res2 = board.Perft(depth, true, hashTable);
OnMessageToWinboard(string.Format("Depth: {3} {0} moves {1:0.00} seconds. {2:0.000} Move/s. Hash Hit={4}", res2.MovesCount, (double)res2.Elapsed / 1000.0, (double)res2.MovesCount / (res2.Elapsed / 1000.0), depth, res2.HashHit));
break;
case "perft":
depth = int.Parse(rPart);
PerfResults res = board.Perft(depth, false, null);
OnMessageToWinboard(string.Format("Depth: {3} {0} moves {1:0.00} seconds. {2:0.000} Move/s", res.MovesCount, (double)res.Elapsed / 1000.0, (double)res.MovesCount / (res.Elapsed / 1000.0), depth));
break;
case "perf":
PerfResults undoRedo;
PerfResults mgen = board.Perf(out undoRedo, 400000);
OnMessageToWinboard(string.Format("Generated {0} moves in {1:0.00} seconds. {2:0.00} Move/s", mgen.MovesCount, (double)mgen.Elapsed / 1000.0, (double)mgen.MovesCount / (mgen.Elapsed / 1000.0)));
OnMessageToWinboard(string.Format("{0} moves Done/Undone in {1:0.00} seconds. {2:0.00} Move/s", undoRedo.MovesCount, (double)undoRedo.Elapsed / 1000.0, (double)undoRedo.MovesCount / (undoRedo.Elapsed / 1000.0)));
break;
case "setboard":
board.SetBoard(rPart);
break;
case "remove":
Break();
board.UndoMove();
board.UndoMove();
break;
case "undo":
board.UndoMove();
break;
case "new":
Break();
force = false;
board.SetBoard("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1");
InitializeEngine();
break;
case "dump":
StringBuilder sb = new StringBuilder();
board.Dump(new StringWriter(sb));
OnMessageToWinboard(sb.ToString());
break;
case "go":
force = false;
AsyncStartPlay();
break;
case "force":
Break();
force = true;
break;
case "black":
Break();
movingSide = Side.Black;
throw new NotImplementedException();
case "white":
Break();
movingSide = Side.White;
throw new NotImplementedException();
case "edit":
Break();
edit = true;
break;
default:
try
{
board.Move(tokens[0]);
}
catch (Exception e)
{
string s = string.Format("Error ({0}):", e.Message);
OnMessageToWinboard(s);
}
break;
}
}
else
{
switch (tokens[0])
{
case "#":
board.SetBoard("/8/8/8/8/8/8/8/8 w KQkq - 0 1");
//engine.Board = board;
editingSide = Side.White;
break;
case ".":
throw new NotImplementedException();
//edit = false;
//engine.OpeningBook = null; // remove opening book
break;
case "c":
editingSide = Side.Black;
break;
default:
break;
}
}
}
