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);
}
public WallDiffNode(AIBoard copy)
{
Board = new AIBoard(copy);
Depth = 0;
MoveMade = "rootnode";
Diff = BoardAnalysis.FindShortestPath(Board, true) - BoardAnalysis.FindShortestPath(Board, false);
}
public override void StartGame(Dictionary <PlayerInfo, int> allPlayersAndScores)
{
_turnAdviser = new TurnAdviser {
MyId = Info.ID
};
_boardAnalysis = new BoardAnalysis {
MyId = Info.ID
};
}
//This returns all walls adjacent to the wall move made in
public List <WallDiffNode> GetChildren()
{
List <WallDiffNode> children = new List <WallDiffNode>();
List <string> adjacentWalls = DictionaryLookup.PerformWallsOfInterestLookup(MoveMade);
foreach (string wall in adjacentWalls)
{
AIBoard tempBoard = new AIBoard(Board);
tempBoard.MakeMove(wall);
if (BoardAnalysis.CheckPathExists(tempBoard, true) && BoardAnalysis.CheckPathExists(tempBoard, false))
{
children.Add(new WallDiffNode(this, wall));
}
}
return(children);
}
//Constructs a list of treenodes that result from every move made that is possible.
//Pruning function (SetNodesOfInterest) will cut of many nodes that are not of interest.
public List <TreeNode> GetChildren()
{
List <TreeNode> children = new List <TreeNode>();
foreach (string move in Board.GetPawnMoves())
{
//This checks to make sure walls are valid
AIBoard tempBoard = new AIBoard(Board);
tempBoard.MakeMove(move);
children.Add(new TreeNode(tempBoard, move));
}
//This gets only valid walls but is done here so that it will only check walls of interest.
//This avoids checking if a ton of walls are valid that we don't care about.
//This is why we do not just call GetWallMoves()
if ((Board.GetIsPlayerOneTurn() && Board.GetPlayerOneNumWalls() == 0) ||
(!Board.GetIsPlayerOneTurn() && Board.GetPlayerTwoNumWalls() == 0))
{
}
else
{
HashSet <string> wallMoves = Board.GetAllValidWalls();
SetNodesOfInterest(ref wallMoves);
foreach (string wall in wallMoves)
{
//This checks to make sure walls are valid
AIBoard tempBoard = new AIBoard(Board);
tempBoard.MakeMove(wall);
if (BoardAnalysis.CheckPathExists(tempBoard, true) && BoardAnalysis.CheckPathExists(tempBoard, false))
{
children.Add(new TreeNode(tempBoard, wall));
}
}
}
//end of wall selection
return(children);
}
public List <string> GetWallMoves()
{
List <string> possibleMoves = new List <string>();
if ((IsPlayerOneTurn && PlayerOneNumWalls == 0) || (!IsPlayerOneTurn && PlayerTwoNumWalls == 0))
{
}
else
{
foreach (string wall in ValidWallPlacements)
{
//This checks to make sure walls are valid
AIBoard tempBoard = new AIBoard(this);
tempBoard.MakeMove(wall);
if (BoardAnalysis.CheckPathExists(tempBoard, true) && BoardAnalysis.CheckPathExists(tempBoard, false))
{
possibleMoves.Add(wall);
}
}
}
return(possibleMoves);
}
//Static evaluation function of the gameboard.
private void EvaluateNode()
{
value = 0;
//If a player won, assigns node proper value and then returns.
if (EvaluateWinPossibility(ref value))
{
}
//Calculates factors of interest and calculates the value.
else
{
int P1SP = BoardAnalysis.FindShortestPath(Board, true);
int P2SP = BoardAnalysis.FindShortestPath(Board, false);
int P1NumWalls = Board.GetPlayerOneNumWalls();
int P2NumWalls = Board.GetPlayerTwoNumWalls();
for (int i = 0; i < P2NumWalls; ++i)
{
value += wallValues[i];
}
value += (weights[0] * P1SP - weights[1] * P2SP);
}
}
//If it is positive P2SP's path got that much shorter.
public int CalcChangeInDiff()
{
Diff = BoardAnalysis.FindShortestPath(Board, true) - BoardAnalysis.FindShortestPath(Board, false);
return(PreviousDiff - Diff);
}
//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);
}
/**
* Returns a list of all possible pawn moves for whichever players turn it is.
**/
public List <string> GetPawnMoves()
{
List <string> possibleMoves;
if (IsPlayerOneTurn)
{
possibleMoves = GetAdjacentMoves(PlayerOneLocation);
foreach (string move in possibleMoves.ToArray())
{
if (PlayerTwoLocation == move)
{
possibleMoves.Remove(move);
string jumpDirection = BoardAnalysis.GetMoveDirection(PlayerOneLocation, PlayerTwoLocation);
List <string> possibleJumps = GetAdjacentMoves(PlayerTwoLocation);
List <string> perpendicularJumps = new List <string>();
string straightJump = "n";
possibleJumps.Remove(PlayerOneLocation);
foreach (string jump in possibleJumps)
{
string possibleDirection = BoardAnalysis.GetMoveDirection(PlayerTwoLocation, jump);
if (possibleDirection == jumpDirection)
{
straightJump = jump;
}
else
{
perpendicularJumps.Add(jump);
}
}
if (straightJump != "n")
{
possibleMoves.Add(straightJump);
}
else
{
possibleMoves.AddRange(perpendicularJumps);
}
break;
}
}
}
else
{
possibleMoves = GetAdjacentMoves(PlayerTwoLocation);
foreach (string move in possibleMoves.ToArray())
{
if (PlayerOneLocation == move)
{
possibleMoves.Remove(move);
string jumpDirection = BoardAnalysis.GetMoveDirection(PlayerTwoLocation, PlayerOneLocation);
List <string> possibleJumps = GetAdjacentMoves(PlayerOneLocation);
List <string> perpendicularJumps = new List <string>();
string straightJump = "n";
possibleJumps.Remove(PlayerTwoLocation);
foreach (string jump in possibleJumps)
{
string possibleDirection = BoardAnalysis.GetMoveDirection(PlayerOneLocation, jump);
if (possibleDirection == jumpDirection)
{
straightJump = jump;
}
else
{
perpendicularJumps.Add(jump);
}
}
if (straightJump != "n")
{
possibleMoves.Add(straightJump);
}
else
{
possibleMoves.AddRange(perpendicularJumps);
}
break;
}
}
}
return(possibleMoves);
}
