/// <summary>
/// Checks if a given move is valid
/// </summary>
/// <param name="board">The game board</param>
/// <param name="point">The point to play in</param>
/// <param name="currentPlayer">The current player's color</param>
/// <returns>True if the move is valid, false otherwise</returns>
public static bool IsValidMove(Disc[,] board, Point point, Disc currentPlayer)
{
if (point == null)
return false;
return board.At(point).IsEmpty() &&
PointsToReverse(board, point, currentPlayer).Count > 0;
}
public Point NextMove(Disc[,] board, Disc playerColor)
{
Point bestMove = new Point(0, 0);
int MaxD = 1;
foreach (Point p in ReversiGame.ValidMoves(board, playerColor))
{
if ((p.X == 7 && p.Y == 7) || (p.X == 7 && p.Y == 0) || (p.X == 0 && p.Y == 7) || (p.X == 0 && p.Y == 0))
{
return p;
}
int score = ReversiGame.Score(ReversiGame.PlayTurn(board, p, playerColor), playerColor);
if (board.At(p) == playerColor)
{
}
if (score > MaxD)
{
bestMove = p;
MaxD = score;
}
}
return bestMove;
}
/// <summary>
/// Counts the number of discs of a given color on the board.
/// (works for Disc.Empty)
/// </summary>
/// <param name="board">The game board</param>
/// <param name="color">The player color</param>
/// <returns>The disc count</returns>
public static int CountDiscs(Disc[,] board, Disc color)
{
int count = 0;
foreach (Point p in board.PointsIterator())
if (board.At(p) == color)
count++;
return count;
}
/// <summary>
/// Counts the number of discs of a given color on the board.
/// (works for Disc.Empty)
/// </summary>
/// <param name="board">The game board</param>
/// <param name="color">The player color</param>
/// <returns>The disc count</returns>
public static int CountDiscs(Disc[,] board, Disc color)
{
return board.PointsIterator().Count(p => board.At(p) == color);
}
/// <summary>
/// Returns the set of points to reverse in a given direction.
/// </summary>
/// <remarks>
/// Returns the consecutive set of discs from the current point
/// to the next same colored point in the given direction.
/// </remarks>
/// <param name="board">The game board</param>
/// <param name="point">The point of the new disc</param>
/// <param name="direction">The direction to scan in</param>
/// <param name="currentPlayer">The current player's color</param>
/// <returns></returns>
public static ISet<Point> ReversedToNext(Disc[,] board, Point point, Point direction, Disc currentPlayer)
{
HashSet<Point> points = new HashSet<Point>();
point += direction;
if (!board.OnBoard(point))
return points;
Disc currentDisc;
for (currentDisc = board.At(point);
currentDisc == currentPlayer.Reversed() && board.OnBoard(point + direction);
point += direction, currentDisc = board.At(point))
points.Add(point);
if (currentDisc.IsEmpty() ||
!board.OnBoard(point + direction) && currentDisc != currentPlayer)
points.Clear();
return points;
}
/// <summary>
/// Returns a set of points to reverse as a result of placing a new disc
/// </summary>
/// <remarks>
/// A move is invalid if the number of points in the set is zero
/// <see cref="ReversiGame.IsValidMove(Disc[,], Point, Disc)"/>
/// </remarks>
/// <param name="board">The game board</param>
/// <param name="newDisc">The new disc's position</param>
/// <param name="currentPlayer">The new disc's color</param>
/// <returns>A set of points to reverse</returns>
public static ISet<Point> PointsToReverse(Disc[,] board, Point newDisc, Disc currentPlayer)
{
if (!board.At(newDisc).IsEmpty())
throw new Exception("Non-empty point chosen to place new disc");
HashSet<Point> result = new HashSet<Point>();
foreach (Point direction in Point.Directions)
result.UnionWith(ReversedToNext(board, newDisc, direction, currentPlayer));
return result;
}
