private int AlphaBeta(int depth, Board board, int alpha, int beta, bool maximizingPlayer)
{
if (depth <= 0 || _valueHeuristic.IsBoardTerminal(board))
{
return(_valueHeuristic.GetHeuristicValue(board, depth, _player));
}
var bestValue = maximizingPlayer ? -1 : 1;
for (var i = 0; i < board.Columns; i++)
{
if (!board.DropCoin(maximizingPlayer ? 2 : 1, i))
{
continue;
}
var value = AlphaBeta(depth - 1, board, alpha, beta, !maximizingPlayer);
if (maximizingPlayer)
{
alpha = Math.Max(alpha, value);
}
else
{
beta = Math.Min(beta, value);
}
bestValue = maximizingPlayer ? Math.Max(bestValue, value) : Math.Min(bestValue, value);
board.RemoveTopCoin(i);
if (alpha >= beta)
{
break;
}
}
return(bestValue);
}
private int MinMax(int depth, Board board, bool maximizingPlayer)
{
if (depth <= 0 || _valueHeuristic.IsBoardTerminal(board))
{
return(_valueHeuristic.GetHeuristicValue(board, depth, _player));
}
var bestValue = maximizingPlayer ? -1 : 1;
for (var i = 0; i < board.Columns; i++)
{
if (!board.DropCoin(maximizingPlayer ? 2 : 1, i))
{
continue;
}
var value = MinMax(depth - 1, board, !maximizingPlayer);
bestValue = maximizingPlayer ? Math.Max(bestValue, value) : Math.Min(bestValue, value);
board.RemoveTopCoin(i);
}
return(bestValue);
}
