protected override int EstimationFunction(MinimaxTreeNode node)
{
// winning condition for me
if (WhoHasMoreBoxes(node, out int blue, out int red) == whoAmI && node.NonExistingLines.Count == 0)
{
return(int.MaxValue);
}
List <Box> newBoxes = AICommon.TryClosingBoxes(node.ExistingLines,
(node.Player == MinimaxPlayerType.MAX ? Player.BLUE : Player.RED),
node.DeltaMove,
out int[] surroundingEdges);
// select state in which user can close boxes
if (newBoxes.Count > 0)
{
return(int.MaxValue - 1);
}
// this state could lead opponent to close the box, hence negative estimation
if (surroundingEdges[0] == 2 && surroundingEdges[1] == 2)
{
return(-2);
}
else if (surroundingEdges[0] == 2 || surroundingEdges[1] == 2)
{
return(-1);
}
// state is neutral for result for the provided tree depth
return(0);
}
protected override int EstimationFunction(MinimaxTreeNode node)
{
int blue, red;
// winning condition for me
if (WhoHasMoreBoxes(node, out blue, out red) == whoAmI && node.NonExistingLines.Count == 0)
{
return(int.MaxValue);
}
// winning condition for opponent
else if (WhoHasMoreBoxes(node, out blue, out red) != whoAmI && node.NonExistingLines.Count == 0)
{
return(int.MinValue);
}
List <Box> newBoxes = AICommon.TryClosingBoxes(node.ExistingLines,
(node.Player == MinimaxPlayerType.MAX ? Player.BLUE : Player.RED),
node.DeltaMove,
out int[] surroundingEdges);
// box closing
if (newBoxes.Count == 1)
{
return(int.MaxValue - 2); // will close one box
}
else if (newBoxes.Count == 2)
{
return(int.MaxValue - 1); // will close two boxes
}
// keep state where I will have more boxes
if ((blue > red && whoAmI == Player.BLUE) || (red > blue && whoAmI == Player.RED))
{
return(int.MaxValue / 2 - Math.Abs(blue - red));
}
// this state could lead opponent to close the box, hence negative estimation
if (surroundingEdges[0] == 2 && surroundingEdges[1] == 2)
{
return(-2);
}
else if (surroundingEdges[0] == 2 || surroundingEdges[1] == 2)
{
return(-1);
}
if ((blue < red && whoAmI == Player.BLUE) || (red < blue && whoAmI == Player.RED))
{
return(int.MinValue / 2 + Math.Abs(blue - red));
}
// state is neutral for result for the provided tree depth
return(0);
}
private void FinishTurn(LineBetweenCircles line)
{
if (line == null)
{
throw new Exception("AI returned null for the next move.");
}
// will return false if clicked on line that had already been drawn on the canvas
if (!TransferFromNonExistingToExisting(line))
{
return;
}
///////////////////////////////////
string log = line.ToString();
int startPosition = turnRichTextBox.Text.Length;
string textToAppend = log + Environment.NewLine;
turnRichTextBox.AppendText(textToAppend);
turnRichTextBox.SelectionStart = startPosition;
turnRichTextBox.SelectionLength = log.Length;
turnRichTextBox.SelectionColor = (currentGame.Turn == Player.BLUE ? Color.Blue : Color.Red);
turnRichTextBox.ScrollToCaret();
///////////////////////////////////
List <Box> newBoxes = AICommon.TryClosingBoxes(existingCanvasLines, currentGame.Turn, line, out int[] notUsed);
boxes.AddRange(newBoxes);
currentGame.Score[(int)currentGame.Turn] += newBoxes.Count;
if (newBoxes.Count > 0)
{
canvas.Refresh();
UpdateGUI();
}
if (boxes.Count == (currentGame.TableSizeX - 1) * (currentGame.TableSizeY - 1))
{
currentGame.GameOver = true;
}
if (currentGame.GameOver)
{
UpdateGUI();
GUI_GameSettingChanged(null, null);
MessageBox.Show("Igra je završena");
}
else if (currentGame.Opponent2 == null) // pc vs pc will be handled in other method -> PcNextStep
{
if (currentGame.Turn == Player.BLUE)
{
if (newBoxes.Count == 0)
{
SwitchTurn();
if (currentGame.Opponent != null)
{
FinishTurn(currentGame.Opponent.MakeTurn());
}
}
UpdateGUI();
}
else
{
if (newBoxes.Count == 0)
{
SwitchTurn();
}
else if (newBoxes.Count > 0 && currentGame.Opponent != null)
{
UpdateGUI();
Thread.Sleep(1000);
FinishTurn(currentGame.Opponent.MakeTurn());
}
UpdateGUI();
}
}
else if (currentGame.Opponent != null && currentGame.Opponent2 != null)
{
if (newBoxes.Count == 0)
{
SwitchTurn();
}
UpdateGUI();
canvas.Refresh();
}
}
private int ConstructTree(MinimaxTreeNode parentNode, int depth, MinimaxPlayerType minimaxPlayer, int alpha, int beta)
{
// return estimation function if max tree depth reached or game is in finished state
if (depth == maxTreeDepth || parentNode.NonExistingLines.Count == 0)
{
return(EstimationFunction(parentNode));
}
if (minimaxPlayer == MinimaxPlayerType.MAX)
{
int bestValue = int.MinValue;
for (int i = 0; i < parentNode.NonExistingLines.Count; i++)
{
#region New Node Creation
MinimaxTreeNode node = new MinimaxTreeNode();
// calculate estimation function only for leaf nodes
node.Player = (parentNode.Player == MinimaxPlayerType.MAX ? MinimaxPlayerType.MIN : MinimaxPlayerType.MAX);
node.ExistingLines.AddRange(parentNode.ExistingLines);
node.ExistingLines.Add(parentNode.NonExistingLines[i]);
node.NonExistingLines.AddRange(parentNode.NonExistingLines);
node.NonExistingLines.Remove(parentNode.NonExistingLines[i]);
node.Boxes.AddRange(parentNode.Boxes);
List <Box> newBoxes = AICommon.TryClosingBoxes(parentNode.ExistingLines, DeterminePlayerColour(node.Player), parentNode.NonExistingLines[i], out int[] notUsed);
node.Boxes.AddRange(newBoxes);
node.DeltaMove = parentNode.NonExistingLines[i];
#endregion
/* don't go through this subtree if the delta move is drawing third edge
* unless it the only move
*/
AICommon.TryClosingBoxes(node.ExistingLines,
DeterminePlayerColour(node.Player),
node.DeltaMove,
out int[] surroundingEdges);
if ((surroundingEdges[0] == 2 || surroundingEdges[1] == 2))
{
if (!(i == parentNode.NonExistingLines.Count - 1 && parentNode.Children.Count == 0))
{
Debug.WriteLine(node.DeltaMove.ToString() + " was thrown.");
continue;
}
}
node.EstimationScore = ConstructTree(node, depth + 1, MinimaxPlayerType.MIN, alpha, beta);
bestValue = (bestValue > node.EstimationScore ? bestValue : node.EstimationScore);
alpha = (alpha > bestValue ? alpha : bestValue);
parentNode.Children.Add(node);
if (beta <= alpha)
{
break;
}
}
parentNode.EstimationScore = bestValue;
return(bestValue);
}
else
{
int bestValue = int.MaxValue;
for (int i = 0; i < parentNode.NonExistingLines.Count; i++)
{
#region New Node Creation
MinimaxTreeNode node = new MinimaxTreeNode();
// calculate estimation function only for leaf nodes
node.Player = (parentNode.Player == MinimaxPlayerType.MAX ? MinimaxPlayerType.MIN : MinimaxPlayerType.MAX);
node.ExistingLines.AddRange(parentNode.ExistingLines);
node.ExistingLines.Add(parentNode.NonExistingLines[i]);
node.NonExistingLines.AddRange(parentNode.NonExistingLines);
node.NonExistingLines.Remove(parentNode.NonExistingLines[i]);
node.Boxes.AddRange(parentNode.Boxes);
List <Box> newBoxes = AICommon.TryClosingBoxes(parentNode.ExistingLines, DeterminePlayerColour(node.Player), parentNode.NonExistingLines[i], out int[] notUsed);
node.Boxes.AddRange(newBoxes);
node.DeltaMove = parentNode.NonExistingLines[i];
#endregion
/* don't go through this subtree if the delta move is drawing third edge
* unless it the only move
*/
AICommon.TryClosingBoxes(node.ExistingLines,
DeterminePlayerColour(node.Player),
node.DeltaMove,
out int[] surroundingEdges);
if ((surroundingEdges[0] == 2 || surroundingEdges[1] == 2))
{
if (!(i == parentNode.NonExistingLines.Count - 1 && parentNode.Children.Count == 0))
{
Debug.WriteLine(node.DeltaMove.ToString() + " was thrown.");
continue;
}
}
node.EstimationScore = ConstructTree(node, depth + 1, MinimaxPlayerType.MAX, alpha, beta);
bestValue = (bestValue < node.EstimationScore ? bestValue : node.EstimationScore);
beta = (beta < bestValue ? beta : bestValue);
parentNode.Children.Add(node);
if (beta <= alpha)
{
break;
}
}
parentNode.EstimationScore = bestValue;
return(bestValue);
}
throw new Exception("Something wrong in minimax happened");
}