private int alphabeta(int depth, int alpha, int beta, char turn)
{
// Takes 95% CPU
int me = GameEngine.Rules.findCaptured(getColor(), getOpponentColor(), boardCopy, boardCopy.GetLength(0)).Count;
int oppo = GameEngine.Rules.findCaptured(getOpponentColor(), getColor(), boardCopy, boardCopy.GetLength(0)).Count;
if (oppo > 0 && me > 0)
{
if (turn == getColor())
{
return(-1000000000);
}
else
{
return(1000000000);
}
}
else if (oppo + me > 0)
{
if (oppo > 0)
{
return(-1000000000);
}
else if (me > 0)
{
return(1000000000);
}
}
if (depth == 0)
{
return(AiUtil.getLiberties(getColor(), boardCopy) - AiUtil.getLiberties(getOpponentColor(), boardCopy));
}
//both player have the same next moves
//List<Point> nextMoves = AiUtil.getNextMoves(boardCopy, influence, 10); //hard coded horizontal pruning
IEnumerable <JokerPoint> nextMoves = AiUtil.getNextMoves(boardCopy, 3);
if (turn == getColor())
{
foreach (JokerPoint next in nextMoves)
{
int priorInf = influence[next.x, next.y];
updateInfluenceMap(next.x, next.y, boardCopy.GetLength(0));
boardCopy[next.x, next.y] = getColor();
int temp = alphabeta(depth - 1, alpha, beta, getOpponentColor());
boardCopy[next.x, next.y] = '*';
restoreInfluenceMap(next.x, next.y, priorInf, boardCopy.GetLength(0));
if (alpha < temp)
{
alpha = temp;
if (depth == this._maxDepth)
{
bestMove = next;
}
}
if (beta <= alpha)
{
return(alpha);
}
}
return(alpha);
}
else
{
foreach (JokerPoint next in nextMoves)
{
int priorInf = influence[next.x, next.y];
updateInfluenceMap(next.x, next.y, boardCopy.GetLength(0));
boardCopy[next.x, next.y] = getOpponentColor();
int temp = alphabeta(depth - 1, alpha, beta, getColor());
boardCopy[next.x, next.y] = '*';
restoreInfluenceMap(next.x, next.y, priorInf, boardCopy.GetLength(0));
if (beta > temp)
{
beta = temp;
if (depth == this._maxDepth)
{
bestMove = next;
}
}
if (beta <= alpha)
{
return(beta);
}
}
return(beta);
}
}
