public int Search(Color playerToMove, int maxPly, int depth, int alpha, int beta)
{
ZobristHash lZobristHash = Board.ZobristHash.Clone();
lZobristHash.Mark(playerToMove);
if (depth > 1)
{
TranspositionTable.Node lNode = TranspositionTable.Retrieve(lZobristHash);
if ((lNode.Flag != TranspositionTable.NodeType.Unknown) && ((maxPly - depth) <= lNode.Height))
{
switch (lNode.Flag)
{
case TranspositionTable.NodeType.Exact:
{
SearchComplete = false;
TranspositionTableHits++;
return(lNode.Value);
}
case TranspositionTable.NodeType.LowerBound:
{
alpha = (alpha > lNode.Value) ? alpha : lNode.Value;
break;
}
case TranspositionTable.NodeType.UpperBound:
{
beta = (beta < lNode.Value) ? beta : lNode.Value;
break;
}
}
if (alpha >= beta)
{
return(lNode.Value);
}
}
}
if ((depth == maxPly) || ((depth != 0) && (SearchInterface.IsGameOver())))
{
if (depth == maxPly)
{
SearchComplete = false;
}
NodesEvaluated++;
int lEval = SearchInterface.Evaluate(playerToMove);
TranspositionTable.Record(maxPly - depth, lEval, TranspositionTable.NodeType.Exact, lZobristHash);
return(lEval);
}
PrincipalVariation.SetPVLength(depth);
MoveList lMoves = SearchInterface.GetMoveList(playerToMove, SearchOptions.IncludeEndGameMoves);
SearchInterface.PruneMoveList(lMoves);
SearchInterface.PrioritizeMoves(lMoves, playerToMove);
if ((SearchOptions.UsePatterns) && (lMoves.Count != 0))
{
PatternMap lPatternMap = SearchOptions.PatternDetector.FindPatterns(Board, playerToMove, lMoves.AllMoves);
lPatternMap.UpdateMoveList(lMoves);
}
if (lMoves.Count == 0)
{
lMoves.Add(CoordinateSystem.PASS);
}
if ((lMoves.Count == 1) && (lMoves[0] == CoordinateSystem.PASS) && (Board.LastMove == CoordinateSystem.PASS))
{
PrincipalVariation.UpdatePV(depth, CoordinateSystem.PASS);
int lEval = SearchInterface.Evaluate(playerToMove);
TranspositionTable.Record(maxPly - depth, lEval, TranspositionTable.NodeType.Exact, lZobristHash);
return(lEval);
}
// follow the principle variation
if (FollowPV)
{
FollowPV = false;
int lPVMove = PrincipalVariation.GetMove(depth);
if (lPVMove != PrincipalVariation.NO_VALUE)
{
if (lMoves.Contains(lPVMove))
{
lMoves.SetValue(lPVMove, Int32.MaxValue);
FollowPV = true;
}
}
}
SearchInterface.SortMoveList(lMoves);
if (UpdateStatusFlag)
{
UpdateStatus();
}
if (StopThinkingFlag)
{
Stop();
}
int lSuperKoCount = 0;
TranspositionTable.NodeType lFlag = TranspositionTable.NodeType.UpperBound;
foreach (int lMove in lMoves)
{
NodesSearched++;
bool lPlayed = Board.PlayStone(lMove, playerToMove, true);
if (!lPlayed)
{
throw new ApplicationException("SearchMethodAB_ID_TT_PVS.cs: You hit a bug!");
}
if ((CheckSuperKo) && (Board.IsSuperKo()))
{
lSuperKoCount++;
Board.Undo();
}
else
{
int lScore = -Search(playerToMove.Opposite, maxPly, depth + 1, -beta, -alpha);
Board.Undo();
if (lScore > alpha)
{
if (lScore >= beta)
{
TranspositionTable.Record(maxPly - depth, alpha, TranspositionTable.NodeType.LowerBound, lZobristHash);
return(lScore);
}
alpha = lScore;
lFlag = TranspositionTable.NodeType.Exact;
PrincipalVariation.UpdatePV(depth, lMove);
}
}
}
if (lSuperKoCount == lMoves.Count)
{
return(SearchInterface.Evaluate(playerToMove));
}
TranspositionTable.Record(maxPly - depth, alpha, lFlag, lZobristHash);
return(alpha);
}
public int Search(Color playerToMove, int maxPly, int depth, int alpha, int beta)
{
if ((depth == maxPly) || ((depth != 0) && (SearchInterface.IsGameOver())))
{
if (depth == maxPly)
{
SearchComplete = false;
}
NodesEvaluated++;
return(SearchInterface.Evaluate(playerToMove));
}
PrincipalVariation.SetPVLength(depth);
MoveList lMoves = SearchInterface.GetMoveList(playerToMove, SearchOptions.IncludeEndGameMoves);
SearchInterface.PruneMoveList(lMoves);
SearchInterface.PrioritizeMoves(lMoves, playerToMove);
if ((SearchOptions.UsePatterns) && (lMoves.Count != 0))
{
PatternMap lPatternMap = SearchOptions.PatternDetector.FindPatterns(Board, playerToMove, MoveList.Randomize(lMoves.AllMoves, SearchOptions.Permutations, depth));
lPatternMap.UpdateMoveList(lMoves);
}
if (lMoves.Count == 0)
{
lMoves.Add(CoordinateSystem.PASS);
}
if ((lMoves.Count == 1) && (lMoves[0] == CoordinateSystem.PASS) && (Board.LastMove == CoordinateSystem.PASS))
{
PrincipalVariation.UpdatePV(depth, CoordinateSystem.PASS);
NodesEvaluated++;
return(SearchInterface.Evaluate(playerToMove));
}
// follow the principle variation
if (FollowPV)
{
FollowPV = false;
int lPVMove = PrincipalVariation.GetMove(depth);
if (lPVMove != PrincipalVariation.NO_VALUE)
{
if (lMoves.Contains(lPVMove))
{
lMoves.SetValue(lPVMove, Int32.MaxValue);
FollowPV = true;
}
}
}
SearchInterface.SortMoveList(lMoves);
if (UpdateStatusFlag)
{
UpdateStatus();
}
if (StopThinkingFlag)
{
Stop();
}
int lSuperKoCount = 0;
foreach (int lMove in lMoves)
{
NodesSearched++;
bool lPlayed = Board.PlayStone(lMove, playerToMove, true);
if (!lPlayed)
{
throw new ApplicationException("SearchMethodAB_ID_PVS.cs: You hit a bug!");
}
if ((CheckSuperKo) && (Board.IsSuperKo()))
{
lSuperKoCount++;
Board.Undo();
}
else
{
int lScore = -Search(playerToMove.Opposite, maxPly, depth + 1, -beta, -alpha);
Board.Undo();
if (lScore > alpha)
{
if (lScore >= beta)
{
return(lScore);
}
alpha = lScore;
PrincipalVariation.UpdatePV(depth, lMove);
}
}
}
if (lSuperKoCount == lMoves.Count)
{
return(SearchInterface.Evaluate(playerToMove));
}
return(alpha);
}
