private Result minimaxVal(Board b, int d, Stopwatch w, int alpha, int beta)
{
if (w.ElapsedMilliseconds > getTimePerMove())
{
throw new MoveTimedOutException();
}
int bestMove = 0;
int bestVal;
bool gameCompleted = false;
if (b.gameOver() || d == 0)
{
return(new Result(0, evaluate(b), b.gameOver()));
}
if (b.whoseMove() == Position.Top)
{
bestVal = Int32.MinValue;
for (int move = 7; move <= 12; move++)
{
if (b.legalMove(move))
{
Board b1 = new Board(b);
b1.makeMove(move, false);
Result val = minimaxVal(b1, d - 1, w, alpha, beta);
if (val.getScore() > bestVal)
{
bestVal = val.getScore();
bestMove = move;
gameCompleted = val.isEndGame();
}
if (bestVal > alpha)
{
alpha = bestVal;
}
}
}
}
else
{
bestVal = Int32.MaxValue;
for (int move = 0; move <= 5; move++)
{
if (b.legalMove(move))
{
Board b1 = new Board(b);
b1.makeMove(move, false);
Result val = minimaxVal(b1, d - 1, w, alpha, beta);
if (val.getScore() < bestVal)
{
bestVal = val.getScore();
bestMove = move;
gameCompleted = val.isEndGame();
}
if (bestVal < beta)
{
beta = bestVal;
}
}
}
}
return(new Result(bestMove, bestVal, gameCompleted));
}
public override int evaluate(Board b)
{
int score = b.stonesAt(13) - b.stonesAt(6);
int stonesTotal = 0;
int goAgainsTotal = 0;
int capturesTotal = 0;
for (int i = 7; i <= 12; i++)
{
int priority = 0;
int target = b.stonesAt(i) % (13 - i);
int targetStonesAt = b.stonesAt(target + 7);
if (b.whoseMove() == Position.Bottom)
{
stonesTotal -= b.stonesAt(i);
if ((b.stonesAt(i) - (13 - i) == 0) || (b.stonesAt(i) - (13 - i)) == 13)
{
goAgainsTotal -= (1 + priority);
}
if (targetStonesAt == 0 && b.stonesAt(i) == (13 - i + target + 7))
{
capturesTotal += (b.stonesAt(i) + b.stonesAt(12 - target));
}
}
else
{
stonesTotal += b.stonesAt(i);
if ((b.stonesAt(i) - (13 - i) == 0) || (b.stonesAt(i) - (13 - i)) == 13)
{
goAgainsTotal += (1 + priority);
}
if (targetStonesAt == 0 && b.stonesAt(i) == (13 - i + target + 7))
{
capturesTotal -= (b.stonesAt(i) + b.stonesAt(12 - target));
}
}
priority++;
}
for (int i = 0; i <= 5; i++)
{
int priority = 0;
int target = b.stonesAt(i) % (13 - i);
int targetStonesAt = b.stonesAt(target);
if (b.whoseMove() == Position.Bottom)
{
stonesTotal += b.stonesAt(i);
if ((b.stonesAt(i) - (6 - i) == 0) || (b.stonesAt(i) - (6 - i)) == 13)
{
goAgainsTotal -= (1 + priority);
}
if (targetStonesAt == 0 && b.stonesAt(i) == (13 - i + target))
{
capturesTotal -= (b.stonesAt(i) + b.stonesAt(12 - target));
}
}
else
{
stonesTotal -= b.stonesAt(i);
if ((b.stonesAt(i) - (6 - i) == 0) || (b.stonesAt(i) - (6 - i)) == 13)
{
goAgainsTotal += (1 + priority);
}
if (targetStonesAt == 0 && b.stonesAt(i) == (13 - i + target))
{
capturesTotal += (b.stonesAt(i) + b.stonesAt(12 - target));
}
}
priority++;
}
score += stonesTotal + capturesTotal + goAgainsTotal;
return(score);
}