private List <float> GetHardWeights(AIBoard board)
{
float p1spWeight = 1f;
float p2spWeight = 1f;
//Variables used in weight calculations.
int playerOneSP = BoardAnalysis.FindShortestPath(board, true);
int playerTwoSP = BoardAnalysis.FindShortestPath(board, true);
int playerTwoNumWalls = CurrentBoard.GetPlayerTwoNumWalls();
int distanceBetweenPlayers = BoardAnalysis.FindDistanceBetween(CurrentBoard, CurrentBoard.GetPlayerOnePos(), CurrentBoard.GetPlayerTwoPos());
if (playerOneSP - playerTwoSP > 2)
{
p1spWeight = 5;
}
else if (playerOneSP < 5)
{
p1spWeight = 2;
}
List <float> w = new List <float> {
p1spWeight, p2spWeight
};
return(w);
}
//Initiates a minimax search 2 layers deep.
public string GetHardMove(string playerMove)
{
timer.Start();
TreeNode.weights = GetHardWeights(CurrentBoard);
TreeNode.wallValues = new List <float> {
2f, 2f, 2f, 2f, 1f, 1f, 1f, 1f, 1f, 0f
};
//AI starts on e9 and makes the first move of the game.
if (playerMove == "gamestart")
{
CurrentBoard.PlayerTwoGoesFirst();
}
//AI starts on e1 and makes the first move of the game.
else if (playerMove == "")
{
}
//Updates the board with the player's move.
else
{
CurrentBoard.MakeMove(playerMove);
}
TreeNode rootNode = new TreeNode(CurrentBoard);
float rootNodeValue = rootNode.CalcValue();
List <TreeNode> possibleMoves = rootNode.GetChildren();
//Create dictionary of all useful values of first two levels of analysis.
Dictionary <string, MoveInfo> moveValues = new Dictionary <string, MoveInfo>();
foreach (TreeNode moveNode in possibleMoves)
{
if (timer.ElapsedMilliseconds > 5980)
{
break;
}
MoveInfo thisMovesInfo = new MoveInfo();
foreach (TreeNode childNode in moveNode.GetChildren())
{
thisMovesInfo.UpdateValues(childNode.CalcValue(), moveNode.CalcValue());
}
moveValues.Add(moveNode.GetMoveMade(), thisMovesInfo);
}
string selectedMove = "none1";
//Minimax of the first two levels.
List <string> movesSelected = new List <string>();
float value = float.NegativeInfinity;
foreach (KeyValuePair <string, MoveInfo> pair in moveValues)
{
if (pair.Value.singleLevelValue > 10000)
{
value = pair.Value.singleLevelValue;
movesSelected.Clear();
movesSelected.Add(pair.Key);
break;
}
if (pair.Value.min > value)
{
value = pair.Value.min;
movesSelected.Clear();
movesSelected.Add(pair.Key);
}
else if (pair.Value.min == value)
{
movesSelected.Add(pair.Key);
}
}
selectedMove = movesSelected[new System.Random().Next(0, movesSelected.Count)];
//If selected move isn't a wall then use the pawn moves single level evaluation.
//And if jump next move isn't a possibility.
bool isPawnMove = !(selectedMove.EndsWith("h") || selectedMove.EndsWith("v"));
bool jumpPossible = BoardAnalysis.FindDistanceBetween(CurrentBoard, CurrentBoard.GetPlayerOnePos(), CurrentBoard.GetPlayerTwoPos()) == 2;
if (isPawnMove && !jumpPossible)
{
List <string> pawnMoves = CurrentBoard.GetPawnMoves();
value = float.NegativeInfinity;
selectedMove = "none2";
foreach (string pm in pawnMoves)
{
float tempVal = moveValues[pm].singleLevelValue;
if (tempVal > value)
{
selectedMove = pm;
value = tempVal;
}
}
}
float testVal = value - rootNodeValue;
if (value - rootNodeValue < 3)
{
float currentPotential = float.NegativeInfinity;
float currentRisk = float.NegativeInfinity;
movesSelected.Clear();
foreach (KeyValuePair <string, MoveInfo> pair in moveValues)
{
if (pair.Key.EndsWith("h") || pair.Key.EndsWith("v"))
{
float optimisticPotential = pair.Value.max - rootNodeValue;
float pessemisticPotential = pair.Value.min - rootNodeValue;
float risk = optimisticPotential - pessemisticPotential;
if (optimisticPotential > 2)
{
if (optimisticPotential > currentPotential)
{
movesSelected.Clear();
movesSelected.Add(pair.Key);
currentPotential = optimisticPotential;
currentRisk = risk;
}
else if (optimisticPotential == currentPotential)
{
if (risk < currentRisk)
{
movesSelected.Clear();
movesSelected.Add(pair.Key);
currentPotential = optimisticPotential;
currentRisk = risk;
}
else if (risk == currentRisk)
{
movesSelected.Add(pair.Key);
}
}
}
}
}
if (movesSelected.Count > 0)
{
selectedMove = movesSelected[new System.Random().Next(0, movesSelected.Count)];
}
}
timer.Reset();
CurrentBoard.MakeMove(selectedMove);
return(selectedMove);
}