private int maxMove(CheckersBoard board, int depth, int alpha, int beta)
{
if (cutOffTest(board, depth))
{
return(eval(board));
}
List sucessors;
List move;
CheckersBoard nextBoard;
int value;
sucessors = board.legalMoves();
while (mayPlay(sucessors))
{
move = (List)sucessors.pop_front();
nextBoard = (CheckersBoard)board.clone();
nextBoard.move(move);
value = minMove(nextBoard, depth + 1, alpha, beta);
if (value > alpha)
{
alpha = value;
}
if (alpha > beta)
{
return(beta);
}
}
return(alpha);
}
private List minimax(CheckersBoard board)
{
List sucessors;
List move, bestMove = null;
CheckersBoard nextBoard;
int value, maxValue = Int32.MinValue;
sucessors = board.legalMoves();
while (mayPlay(sucessors))
{
move = (List)sucessors.pop_front();
nextBoard = (CheckersBoard)board.clone();
nextBoard.move(move);
value = minMove(nextBoard, 1, maxValue, Int32.MaxValue);
if (value > maxValue)
{
maxValue = value;
bestMove = move;
}
}
return(bestMove);
}