public static void ExpertMove(GameBoard board, GameBoard aiboard, Player player, TicTacToeGameRules myGameRules, out int row, out int col)
{
row = 0;
col = 0;
int bestScore = -1;
int score;
aiboard.InitializeGameBoard();
if (board.rows == 3 && board.cols == 3 && board.GetGameBoardSpace(1, 1) == " ")
{
row = 1;
col = 1;
}
else
{
for (int y = 0; y < board.rows; y++)
{
for (int x = 0; x < board.cols; x++)
{
if (board.GetGameBoardSpace(y, x) == " ")
{
board.SetGameBoardSpace(y, x, player.myPiece);
score = Minimax(board, myGameRules.minimaxDepth, false, y, x, -1, myGameRules);
board.SetGameBoardSpace(y, x, " ");
if (score > bestScore)
{
bestScore = score;
}
aiboard.SetGameBoardSpace(y, x, score.ToString());
//aiGameBoard.DrawGameBoard();
}
}
}
// See scores
//aiboard.DrawGameBoard();
//Console.WriteLine($"bestScore = {bestScore}");
//Console.ReadLine();
// Pick Random From Best
Random rand = new Random();
do
{
row = rand.Next(board.rows);
col = rand.Next(board.cols);
} while (aiboard.GetGameBoardSpace(row, col) != bestScore.ToString());
}
}
private bool PlacePiece(GameBoard board, int row, int col, Player player)
{
if (row >= 0 && row < board.rows && col >= 0 && col < board.cols && board.GetGameBoardSpace(row, col) == " ")
{
board.SetGameBoardSpace(row, col, player.myPiece);
return(true);
}
else
{
if (player.myType == "Human")
{
Console.WriteLine(" Invalid space -- try again.");
}
return(false);
}
}
private static int Minimax(GameBoard board, int depth, bool isMaximizing, int row, int col, int parentBestScore, TicTacToeGameRules myGameRules)
{
int maxScore = 1;
int minScore = -1;
int score;
// See move
//board.DrawGameBoard();
//Console.ReadLine();
if (TicTacToeGameRules.CheckForWin(board, row, col, myGameRules.currentPlayer.myPiece))
{
score = 1;
return(score);
}
else if (TicTacToeGameRules.CheckForWin(board, row, col, myGameRules.opponent.myPiece))
{
score = -1;
return(score);
}
else if (TicTacToeGameRules.CheckForDraw(board) || depth <= 0)
{
score = 0;
return(score);
}
if (isMaximizing)
{
int bestScore = minScore;
for (int y = 0; y < board.rows; y++)
{
for (int x = 0; x < board.cols; x++)
{
if (board.GetGameBoardSpace(y, x) == " ")
{
board.SetGameBoardSpace(y, x, myGameRules.currentPlayer.myPiece);
score = Minimax(board, depth - 1, false, y, x, minScore, myGameRules);
board.SetGameBoardSpace(y, x, " ");
if (score > bestScore)
{
bestScore = score;
}
if (bestScore >= parentBestScore)
{
return(bestScore);
}
}
}
}
return(bestScore);
}
else
{
int bestScore = maxScore;
for (int y = 0; y < board.rows; y++)
{
for (int x = 0; x < board.cols; x++)
{
if (board.GetGameBoardSpace(y, x) == " ")
{
board.SetGameBoardSpace(y, x, myGameRules.opponent.myPiece);
score = Minimax(board, depth - 1, true, y, x, maxScore, myGameRules);
board.SetGameBoardSpace(y, x, " ");
if (score < bestScore)
{
bestScore = score;
}
if (bestScore <= parentBestScore)
{
return(bestScore);
}
}
}
}
return(bestScore);
}
}
