/// <summary>
/// Evaluates the board
/// </summary>
/// <param name="board">Provided board</param>
/// <param name="isRed">Is player red's turn</param>
/// <returns></returns>
public static int Evaluate(Board board, bool isRed)
{
// evaluation value
int lEvaluationValue = 0;
// starttime
DateTime lStartTime = DateTime.Now;
// if won, we don't have to do things
if (board.IsWon())
lEvaluationValue = 1000000;
else
{
if (board.IsTileMoved)
{
List<Board> nextMoves = board.GenerateMoves(isRed);
if (nextMoves.Count == 1)
{
return nextMoves[0].Evaluation(isRed, isRed);
}
}
// temp values
int lEmptySpots = 0;
int lOwnHead = 0;
// temp value for storing the to be checked head position
BoardPosition lHead = BoardPosition.RedHead;
if (!isRed)
lHead = BoardPosition.WhiteHead;
// loop trough board
for (int x = 0; x < 21; x++)
{
for (int y = 0; y < 20; y++)
{
//if (boardPositions[x, y] == lHead)
// lOwnHead++;
#region "Check if piece belongs to current player"
bool lCheck = false;
if (board.BoardSituation[x, y] != BoardPosition.Empty && board.BoardSituation[x, y] != BoardPosition.Tile)
{
if (isRed)
{
if (board.BoardSituation[x, y] == BoardPosition.RedHead || board.BoardSituation[x, y] == BoardPosition.RedTail)
lCheck = true;
}
else if (!isRed)
{
if (board.BoardSituation[x, y] == BoardPosition.WhiteHead || board.BoardSituation[x, y] == BoardPosition.WhiteTail)
lCheck = true;
}
}
#endregion
if (lCheck)
{
#region "Left Column"
// x - -
// x - -
// x - -
if (x > 0)
{
// x - -
// - - -
// - - -
if (y > 0)
{
if (board.BoardSituation[x - 1, y - 1] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x - 1, y - 1] == lHead)
lOwnHead++;
}
// - - -
// x - -
// - - -
if (board.BoardSituation[x - 1, y] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x - 1, y] == lHead)
lOwnHead++;
// - - -
// - - -
// x - -
if (y < (20 - 1))
{
if (board.BoardSituation[x - 1, y + 1] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x - 1, y + 1] == lHead)
lOwnHead++;
}
}
#endregion
#region "Middle column"
// - x -
// - x -
// - x -
// - x -
// - - -
// - - -
if (y > 0)
{
if (board.BoardSituation[x, y - 1] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x, y - 1] == lHead)
lOwnHead++;
}
// - - -
// - x -
// - - -
// needs no check, is this position
// - - -
// - - -
// - x -
if (y < (20 - 1))
{
if (board.BoardSituation[x, y + 1] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x, y + 1] == lHead)
lOwnHead++;
}
#endregion
#region "Right column"
// - - x
// - - x
// - - x
if (x < (21 - 1))
{
// - - x
// - - -
// - - -
if (y > 0)
{
if (board.BoardSituation[x + 1, y - 1] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x + 1, y - 1] == lHead)
lOwnHead++;
}
// - - -
// - - x
// - - -
if (board.BoardSituation[x + 1, y] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x + 1, y] == lHead)
lOwnHead++;
// - - -
// - - -
// - - x
if (y < (20 - 1))
{
if (board.BoardSituation[x + 1, y + 1] == BoardPosition.Tile)
lEmptySpots++;
else if (board.BoardSituation[x + 1, y + 1] == lHead)
lOwnHead++;
}
}
#endregion
}
}
}
// calculate evalution value
int evalAdd = 0;
if (Game.Instance.CurrentPlayerNumPieces() > 0)
{
//evalAdd = (lEmptySpots * (lOwnHead / Game.Instance.CurrentPlayerNumPieces()));
evalAdd = lEmptySpots * (lOwnHead ^ 2);
}
lEvaluationValue = lEmptySpots + evalAdd;
}
#region "debug"
//DateTime lStopTime = DateTime.Now;
//TimeSpan lDiff = lStopTime - lStartTime;
//Logger.AddLine("Board -> Evaluation value: " + lEvaluationValue + " (calculated in: " + lDiff.TotalMilliseconds + " ms)");
#endregion
return lEvaluationValue;
}
private int MiniMaxFunction(Board node, int depth, bool isPlayerAMax, bool turnPlayerA)
{
if (depth <= 0 || node.IsWon())
{
return node.Evaluation(isPlayerAMax, turnPlayerA);
}
if (this.transtable)
{
if(table.IsCalculatedBefore(node, depth, isPlayerAMax, turnPlayerA))
return table.GetCalculatedValue(node, depth, isPlayerAMax, turnPlayerA);
}
int alpha = Int32.MinValue;
List<Board> possibleMoves = node.GenerateMoves(turnPlayerA);
turnPlayerA = !turnPlayerA;
if (possibleMoves.Count == 0)
throw new Exception();
foreach (Board board in possibleMoves)
{
if (turnPlayerA == isPlayerAMax)
{
if(board.IsTileMoved)
alpha = Math.Max(alpha, MiniMaxFunction(board, depth - 1, isPlayerAMax, !turnPlayerA));
else
alpha = Math.Max(alpha, MiniMaxFunction(board, depth - 1, isPlayerAMax, turnPlayerA));
}
else
{
if(board.IsTileMoved)
alpha = Math.Max(alpha, -MiniMaxFunction(board, depth - 1, isPlayerAMax, !turnPlayerA));
else
alpha = Math.Max(alpha, -MiniMaxFunction(board, depth - 1, isPlayerAMax, turnPlayerA));
}
}
if(this.transtable)
{
table.InsertCalculatedValue(node, depth, isPlayerAMax, !turnPlayerA, alpha);
}
return alpha;
}
private int AlphaBetaFunction(Board node, int depth, bool isPlayerAMax, bool turnPlayerA, int alphaEval, int betaEval)
{
if (node.IsWon() || depth <= 0)
{
return node.Evaluation(isPlayerAMax, turnPlayerA);
}
if (this.transtable)
{
if (table.IsCalculatedBefore(node, depth, isPlayerAMax, turnPlayerA))
return table.GetCalculatedValue(node, depth, isPlayerAMax, turnPlayerA);
}
int value = Int32.MinValue;
List<Board> possibleMoves = node.GenerateMoves(turnPlayerA);
turnPlayerA = !turnPlayerA;
if (isPlayerAMax == turnPlayerA)
possibleMoves = Order(possibleMoves, true, true);
else
possibleMoves = Order(possibleMoves, false, false);
foreach (Board board in possibleMoves)
{
if (turnPlayerA == isPlayerAMax)
{
if(board.IsTileMoved)
value = Math.Max(value, AlphaBetaFunction(board, depth - 1, isPlayerAMax, !turnPlayerA, alphaEval, betaEval));
else
value = Math.Max(value, AlphaBetaFunction(board, depth - 1, isPlayerAMax, turnPlayerA, alphaEval, betaEval));
alphaEval = Math.Max(value, alphaEval);
if (betaEval <= alphaEval)
{
if (this.transtable)
table.InsertCalculatedValue(node, depth, isPlayerAMax, !turnPlayerA, alphaEval);
return alphaEval;
}
}
else
{
if(board.IsTileMoved)
value = Math.Max(value, -AlphaBetaFunction(board, depth - 1, isPlayerAMax, !turnPlayerA, alphaEval, betaEval));
else
value = Math.Max(value, -AlphaBetaFunction(board, depth - 1, isPlayerAMax, turnPlayerA, alphaEval, betaEval));
betaEval = Math.Min(value, betaEval);
if (betaEval <= alphaEval)
{
if (this.transtable)
table.InsertCalculatedValue(node, depth, isPlayerAMax, !turnPlayerA, betaEval);
return betaEval;
}
}
}
if (this.transtable)
table.InsertCalculatedValue(node, depth, isPlayerAMax, !turnPlayerA, value);
return value;
}
/// <summary>
/// Evaluates the board
/// </summary>
/// <param name="board">Provided board</param>
/// <param name="isRed">Is player red's turn</param>
/// <returns></returns>
public static int Evaluate(Board board, bool isPlayerAMax, bool turnPlayerA)
{
// evaluation value
int lEvaluationValue = 0;
// starttime
DateTime lStartTime = DateTime.Now;
// if won, we don't have to do things
if (board.IsWon())
if (isPlayerAMax == turnPlayerA)
lEvaluationValue = -140;
else
lEvaluationValue = 140;
else
{
// check if tile moved, if so, return evaluation value of next board of tile moved
if (board.IsTileMoved)
{
List<Board> nextMoves = board.GenerateMoves(turnPlayerA);
if (nextMoves.Count > 0)
{
return nextMoves[0].Evaluation(isPlayerAMax, !turnPlayerA);
}
}
else
{
// tiles not moves, so we can continue here
List<PieceSituation> goodSituations = FindSituations(board.BoardSituation, turnPlayerA);
List<PieceSituation> badSituations = FindSituations(board.BoardSituation, !turnPlayerA);
if (goodSituations.Count > 0)
{
IOrderedEnumerable<PieceSituation> orderedGood = from e in goodSituations orderby e select e;
if (orderedGood.First() == PieceSituation.ThreeHeads)
lEvaluationValue = 100;
else if (orderedGood.First() == PieceSituation.ThreeHeadsWithSpace)
lEvaluationValue = 60;
else if (orderedGood.First() == PieceSituation.ThreeHeadsBlocked)
lEvaluationValue = 20;
}
else if (badSituations.Count > 0)
{
IOrderedEnumerable<PieceSituation> orderedBad = from e in badSituations orderby e select e;
if (orderedBad.First() == PieceSituation.ThreeHeads)
lEvaluationValue = -100;
else if (orderedBad.First() == PieceSituation.ThreeHeadsWithSpace)
lEvaluationValue = -60;
else if (orderedBad.First() == PieceSituation.ThreeHeadsBlocked)
lEvaluationValue = -20;
}
}
}
// add amount of head times 5 to eval value
int addToEval = 0;
if (turnPlayerA)
addToEval += 5 * board.RedHeads;
else
addToEval += 5 * board.WhiteHeads;
return (lEvaluationValue + addToEval);
}