/// <summary>
/// Constructs a new Node
/// </summary>
/// <param name="b">The board that the Node will use to evaluate itself and generate its children</param>
/// <param name="parent">The parent of this node</param>
/// <param name="move">The move from the parent's board that generated this node's board</param>
public Node(Board b, Node parent, TicTacToeMove move)
{
this.board = b;
this.parent = parent;
this.move = move;
if (parent != null)
myPiece = Board.GetOponentPiece(parent.MyPiece);
children = new List<Node>();
}
public Node()
{
board = new char[3, 3];
for (int i = 0; i < 3; i++)
{
for(int j = 0; j < 3; j++)
{
board[i, j] = '-';
}
}
parent = null;
}
/// <summary>
/// Begin the game and pass control to the first player
/// </summary>
public void Start()
{
if (_isInitialized)
{
throw new StartGameException("Cannot start game because game has already started.");
}
Node<Player> prevPlayerNode = null;
Node<Player> lastPlayerNode = null;
// Generic way of instantiating active player node (supports more than 2 players)
for (int i = _players.Count - 1; i >= 0; i--)
{
Node<Player> curPlayerNode = new Node<Player>(_players[i], prevPlayerNode);
if (lastPlayerNode == null)
{
lastPlayerNode = curPlayerNode;
}
if (i == 0)
{
_activePlayerNode = curPlayerNode;
}
prevPlayerNode = curPlayerNode;
}
lastPlayerNode.Next = _activePlayerNode;
_isInitialized = true;
OnGameUpdate();
ActivePlayer.PromptForMove(this);
}
protected void AdvanceTurn()
{
_activePlayerNode = _activePlayerNode.Next;
}
// Paint the panel (Draw the board).
private void panel1_Paint(object sender, PaintEventArgs e)
{
base.OnPaint(e);
Pen blackpen = new Pen(Color.Black, 3);
Graphics g = e.Graphics;
int offset = 40;
g.DrawLine(blackpen, new Point(top_left.X, top_left.Y - offset), new Point(bottom_left.X, bottom_left.Y + offset));
g.DrawLine(blackpen, new Point(top_right.X, top_right.Y - offset), new Point(bottom_right.X, bottom_right.Y + offset));
g.DrawLine(blackpen, new Point(top_left.X - offset, top_left.Y), new Point(top_right.X + offset, top_right.Y));
g.DrawLine(blackpen, new Point(bottom_left.X - offset, bottom_left.Y), new Point(bottom_right.X + offset, bottom_right.Y));
drawBoard(node.board, g);
// If the user just won, ask if they want to play again.
string text = "";
if (node.justWon() || node.justWon(false) || node.gameOver())
{
if (node.justWon() || node.justWon(false))
{
string winner = "o";
if (node.justWon() && node.justMovedChar() == 'x')
winner = "x";
text = winner + " Wins!";
}
else
text = "It was a draw";
MessageBoxButtons button = MessageBoxButtons.YesNo;
DialogResult result = MessageBox.Show(text + "\n Play again?", "Game has ended", button);
if (result == DialogResult.Yes)
node = new Node();
else
Application.Exit();
panel1.Invalidate();
}
g.Dispose();
}
// This function handles the mouse click, calls the function to get the computer's move, then updates the board.
private void panel1_MouseClick(Object sender, MouseEventArgs e)
{
var selection = getBox(new Point(e.X, e.Y));
if (validateMove(selection, node.board))
node = node.playerMove(selection.Item1, selection.Item2);
numNodesLabel.Text = "" + Node.nodesVisited;
this.numNodesLabel.Invalidate();
this.panel1.Invalidate();
}
/// <summary>
/// Constructs a MIN node
/// </summary>
/// <param name="b">The board that this node represents</param>
/// <param name="parent">This node's parent</param>
/// <param name="m">The move that was made from the parent to lead to this node's board</param>
public MinNode(Board b, Node parent, TicTacToeMove m)
:base(b, parent, m)
{
}
/// <summary>
/// Selects the best move node for the node
/// </summary>
public void SelectBestMove()
{
// if no children there is no best move for the node
if (children.Count == 0)
{
bestMoveNode = null;
return;
}
// sort the children so that the first element contains the 'best' node
List<Node> sortedChildren = SortChildren(this.children);
this.bestMoveNode = sortedChildren[0];
Value = bestMoveNode.Value;
}
