public static Position GetBestMove(Board board)
{
int bestValue = int.MinValue;
Position bestMove = new Position(-1, -1);
for (int row = 0; row < board.BOARD_DIMENSION; row++)
{
for (int column = 0; column < board.BOARD_DIMENSION; column++)
{
if (board.IsSpaceEmpty(row, column))
{
board.UpdateBoard(row, column, (State)Players.PlayerTwo);
int moveValue = Minimax.MinimaxCheck(board, 1, false);
board.UpdateBoard(row, column, State.Empty);
if (moveValue > bestValue)
{
bestMove = new Position(row, column);
bestValue = moveValue;
}
}
}
}
return(bestMove);
}
public static int MinimaxCheck(Board board, int depth, bool maxComputer)
{
//Thread.Sleep(1000);
int score = Minimax.GetWin(board);
// if there is a win or loss
if (score == 10 || score == -10)
{
return(score - depth);
}
// if the game is over without a winner (draw)
if (board.HasEmptySpaces() == false)
{
return(0 - depth);
}
// runs if it's the computer's turn
if (maxComputer)
{
int currentBest = int.MinValue;
for (int row = 0; row < board.BOARD_DIMENSION; row++)
{
for (int column = 0; column < board.BOARD_DIMENSION; column++)
{
if (board.IsSpaceEmpty(row, column))
{
board.UpdateBoard(row, column, (State)Players.PlayerTwo);
currentBest = Math.Max(currentBest, Minimax.MinimaxCheck(board, depth + 1, !maxComputer));
board.UpdateBoard(row, column, State.Empty);
}
}
}
return(currentBest);
}
else // runs if it's the player's turn
{
int currentBest = int.MaxValue;
for (int row = 0; row < board.BOARD_DIMENSION; row++)
{
for (int column = 0; column < board.BOARD_DIMENSION; column++)
{
if (board.IsSpaceEmpty(row, column))
{
board.UpdateBoard(row, column, (State)Players.PlayerOne);
currentBest = Math.Min(currentBest, Minimax.MinimaxCheck(board, depth + 1, !maxComputer));
board.UpdateBoard(row, column, State.Empty);
}
}
}
return(currentBest);
}
}
public static void PlayGame()
{
Game currentGame = new Game();
while (currentGame.ContinuePlaying && currentGame.TurnsTaken < Game.TURNS)
{
currentGame.UpdateGame();
currentGame.TurnsTaken++;
Position computersNextMove = Minimax.GetBestMove(currentGame.Board);
currentGame.Board.UpdateBoard(computersNextMove.Row, computersNextMove.Column, State.X);
currentGame.Board.PrintBoard();
if (currentGame.Board.IsTheWinner(currentGame.ActivePlayer))
{
currentGame.ContinuePlaying = false;
}
currentGame.ChangeActivePlayer();
currentGame.TurnsTaken++;
}
currentGame.PrintWinner();
}