public static AbstractBoard.Player GetOponentPiece(AbstractBoard.Player yourPiece)
{
if (yourPiece == AbstractBoard.Player.X)
return AbstractBoard.Player.O;
else if (yourPiece == AbstractBoard.Player.O)
return AbstractBoard.Player.X;
else
throw new Exception("Invalid Piece!");
}
protected AbstractBoard.Player opponentPiece; // the opponents piece
public Node(AbstractBoard b, Node parent, Space move)
{
this.board = b.Clone();
this.parent = parent;
this.move = move;
if (parent != null)
myPiece = AbstractBoard.GetOponentPiece(parent.myPiece);
children = new List<Node>();
}
private void mediumBoard_Load(object sender, EventArgs e)
{
gb = new _4by4();
this.LoadBoard();
cell1.Enabled = true;
cell2.Enabled = true;
cell3.Enabled = true;
cell4.Enabled = true;
cell5.Enabled = true;
cell6.Enabled = true;
cell7.Enabled = true;
cell8.Enabled = true;
cell9.Enabled = true;
}
private void GUI_Load(object sender, EventArgs e)
{
gb = new tictactoe();
this.LoadBoard();
cell1.Enabled = true;
cell2.Enabled = true;
cell3.Enabled = true;
cell4.Enabled = true;
cell5.Enabled = true;
cell6.Enabled = true;
cell7.Enabled = true;
cell8.Enabled = true;
cell9.Enabled = true;
}
// create virtual board
//setup virtual game and play.
//sub nodes for each tree .
//recursive method
public static Space GetBestMove(AbstractBoard gb, AbstractBoard.Player p)
{
Space? bestSpace = null;List<Space> openSpaces = gb.OpenSquares;
AbstractBoard newBoard;
for (int i = 0; i < openSpaces.Count; i++)
{
newBoard = gb.Clone();
Space newSpace = openSpaces[i];
newBoard[newSpace.X, newSpace.Y] = p;
if (newBoard.Winner == AbstractBoard.Player.Open && newBoard.OpenSquares.Count > 0)
{
Space tempMove = GetBestMove(newBoard, ((AbstractBoard.Player)(-(int)p)));
newSpace.Rank = tempMove.Rank;
}
else
{
if (newBoard.Winner == AbstractBoard.Player.Open)
newSpace.Rank = 0;
else if (newBoard.Winner == AbstractBoard.Player.X)
newSpace.Rank = -1;
else if (newBoard.Winner == AbstractBoard.Player.O)
newSpace.Rank = 1;
}
//If the new move is better than our previous move, take it
if (bestSpace == null ||
(p == AbstractBoard.Player.X && newSpace.Rank < ((Space)bestSpace).Rank) ||
(p == AbstractBoard.Player.O && newSpace.Rank > ((Space)bestSpace).Rank))
{
bestSpace = newSpace;
}
}
return (Space)bestSpace;
}
private double EvaluateDiagonals(AbstractBoard b, AbstractBoard.Player p)
{
// go down and to the right diagonal first
int count = 0;
bool diagonalClean = true;
double score = 0.0;
for (int i = 0; i < b.COLUMNS; i++)
{
AbstractBoard.Player boardPiece = b[i, i];
if (boardPiece == p)
count++;
if (boardPiece == AbstractBoard.GetOponentPiece(p))
{
diagonalClean = false;
break;
}
}
if (diagonalClean && count > 0)
score += count;// Math.Pow(count, count);
// now try the other way
int row = 0;
int col = 2;
count = 0;
diagonalClean = true;
while (row < b.ROWS && col >= 0)
{
AbstractBoard.Player boardPiece = b[row, col];
if (boardPiece == p)
count++;
if (boardPiece == AbstractBoard.GetOponentPiece(p))
{
diagonalClean = false;
break;
}
row++;
col--;
}
if (count > 0 && diagonalClean)
score += count;
return score;
}
private double EvaluateColumns(AbstractBoard b, AbstractBoard.Player p)
{
int cols = b.COLUMNS;
int rows = b.ROWS;
double score = 0.0;
int count;
for (int j = 0; j < b.COLUMNS; j++)
{
count = 0;
bool rowClean = true;
for (int i = 0; i < b.COLUMNS; i++)
{
AbstractBoard.Player boardPiece = b[i, j];
if (boardPiece == p)
count++;
else if (boardPiece == AbstractBoard.GetOponentPiece(p))
{
rowClean = false;
break;
}
}
if (rowClean && count != 0)
score += count; //Math.Pow(count, count);
}
return score;
}
public double evaluateRows(AbstractBoard b, AbstractBoard.Player p)
{
int cols = b.COLUMNS;
int rows = b.ROWS;
double score = 0.0;
int count;
// check the rows
for (int i = 0; i < b.ROWS; i++)
{
count = 0;
bool rowClean = true;
for (int j = 0; j < b.COLUMNS; j++)
{
AbstractBoard.Player boardPiece = b[i, j];
if (boardPiece == p)
count++;
else if (boardPiece == AbstractBoard.GetOponentPiece(p))
{
rowClean = false;
break;
}
}
// if we get here then the row is clean (an open row)
if (rowClean && count != 0)
score += count;
}
return score;
}
// sums up all the possible ways to win for the specified board piece
private double EvaluatePiece(AbstractBoard b, AbstractBoard.Player p)
{
return evaluateRows(b, p) + EvaluateColumns(b, p) + EvaluateDiagonals(b, p);
}
public double Evaluate(AbstractBoard b, AbstractBoard.Player maxPiece)
{
functionCalls++;
if (b.Winner == AbstractBoard.Player.Open || b.Winner == AbstractBoard.Player.O || b.Winner == AbstractBoard.Player.X)
{
if (b.Winner == maxPiece)
return double.MaxValue;
else
return double.MinValue;
}
double maxValue = EvaluatePiece(b, maxPiece);
double minValue = EvaluatePiece(b, AbstractBoard.GetOponentPiece(maxPiece));
return maxValue - minValue;
}