public moveData generateTree(string[] newGameBoard, int piece, Piece[] currentPieces, int difficulty)
{
int piecesOnBoard;
int maxDepth;
int positionToBlock;
bool boardBlockable = false;
string moveToSend;
string pieceOnDeck;
Node newNode = new Node();
newNode.gameBoard = newGameBoard;
newNode.pieceToPlay = piece;
root = newNode;
Node currentNode = root;
Node parentNode;
parentNode = currentNode;
currentNode.pieces = currentPieces;
positionToBlock = AIFunctions.findWinningPositionToBlock(newGameBoard, currentPieces[piece].piece);
if (difficulty == 3 && positionToBlock != -1 && Heuristic.calculateHeuristic(newGameBoard, currentPieces[piece].piece) > 0)
{
boardBlockable = true;
}
// Sets tree depth according to how many pieces are on the board
piecesOnBoard = AIFunctions.countPiecesOnBoard(newGameBoard);
maxDepth = AIFunctions.setTreeDepth(piecesOnBoard, difficulty);
// Generates game tree
generateChildrenGamestate(currentNode, parentNode, piece, maxDepth, 0);
// Finds the best move in the game tree based on a heuristic.
winningMove move = NegaMax.searchForBestPlay(currentNode, maxDepth, 0, -MAXGAMEBOARD, MAXGAMEBOARD, true);
if (boardBlockable && !move.isWin && piecesOnBoard != MAXGAMEBOARD - 1)
{
// Erases old winning move then adds new move to board.
// Also sets old piece to playable again.
move.winningNode.gameBoard[move.winningNode.moveOnBoard] = null;
move.winningNode.gameBoard[positionToBlock] = currentPieces[piece].piece;
move.winningNode.pieces[move.winningNode.pieceToPlay].setPlayable(true);
move.winningNode = AIFunctions.checkForOpponentWin(move.winningNode, currentPieces[piece].piece);
pieceOnDeck = move.winningNode.pieceToPlay == NULLPIECE?
NULLPIECE.ToString() : move.winningNode.pieces[move.winningNode.pieceToPlay].piece;
moveToSend = move.winningNode.pieces[positionToBlock].piece;
}
else
{
if (piecesOnBoard != 0 && move.winningNode.pieceToPlay != NULLPIECE)
{
move.winningNode = AIFunctions.checkForOpponentWin(move.winningNode, null);
}
moveToSend = move.winningNode.pieces[move.winningNode.moveOnBoard].piece;
//Checks for win by opponent, given the piece chosen
//If win it makes it equal to the next child and so on
pieceOnDeck = move.winningNode.pieceToPlay == NULLPIECE?
NULLPIECE.ToString() : move.winningNode.pieces[move.winningNode.pieceToPlay].piece;
}
return(new moveData
{
lastMoveOnBoard = moveToSend,
pieceToPlay = pieceOnDeck
});
}
public moveData generateTree(string[] newGameBoard, int piece, Piece[] currentPieces, int difficulty)
{
// hashing function would go here
// Followed by a lookup in the transposition table
//HashFunction.ZobristHash zash = new HashFunction.ZobristHash();
//zash.init_zobristHash();
totalGamestates = 0;
int piecesOnBoard;
int maxDepth;
int positionToBlock;
bool boardBlockable = false;
string moveToSend;
positionToBlock = AIFunctions.findWinningPositionToBlock(newGameBoard, currentPieces[piece].piece);
if (difficulty == 3 && positionToBlock != -1 && Heuristic.calculateHeuristic(newGameBoard, currentPieces[piece].piece) > 0)
{
boardBlockable = true;
}
Node newNode = new Node();
newNode.gameBoard = newGameBoard;
newNode.pieceToPlay = piece;
root = newNode;
Node currentNode = root;
Node parentNode;
parentNode = currentNode;
currentNode.pieces = currentPieces;
// Sets tree depth according to how many pieces are on the board
piecesOnBoard = AIFunctions.countPiecesOnBoard(newGameBoard);
maxDepth = AIFunctions.setTreeDepth(piecesOnBoard, difficulty);
generateChildrenGamestate(currentNode, parentNode, piece, maxDepth, 0);
winningMove move = NegaMax.searchForBestPlay(currentNode, maxDepth, 0, -MAXGAMEBOARD, MAXGAMEBOARD, true);
//Checks for win by opponent, given the piece chosen
//If win it makes it equal to the next child and so on
if (piecesOnBoard != 0 && move.winningNode.pieceToPlay != NULLPIECE && difficulty > 1)
{
move.winningNode = AIFunctions.checkForOpponentWin(move.winningNode);
}
// This is bad but it works.
string pieceOnDeck = move.winningNode.pieceToPlay == NULLPIECE?
NULLPIECE.ToString() : move.winningNode.pieces[move.winningNode.pieceToPlay].piece;
if (boardBlockable)
{
moveToSend = move.winningNode.pieces[positionToBlock].piece;
}
else
{
moveToSend = move.winningNode.pieces[move.winningNode.moveOnBoard].piece;
}
return(new moveData
{
lastMoveOnBoard = moveToSend,
pieceToPlay = pieceOnDeck
});
}
