class CGame
{
public:
	INT16 board[3][3];
	BOOL WHOSE_Turn;
	INT16 Judge();
	void ChanegTurn();
	void StepBoard(int i,int j);
	void ClearLastStep(int i,int j);
	void output();
};

INT16 CGame::Judge()
{
	for(int i = 0;i < 3;i++)
	{
		if(board[i][0] != EMPTY && 
		   board[i][1] == board[i][0] && 
		   board[i][2] == board[i][0])
			return board[i][0];//横向分出胜负

		if(board[0][i] != EMPTY && 
		   board[1][i] == board[0][i] && 
		   board[2][i] == board[0][i])
			return board[0][i];//纵向分出胜负
	}

	if(board[0][0] != EMPTY &&
	   board[1][1] == board[0][0] &&
	   board[2][2] == board[0][0])
		return board[0][0];//主对角线分出胜负

	if(board[2][0] != EMPTY && 
	   board[1][1] == board[2][0] && 
	   board[0][2] == board[2][0])
		return board[2][0];//副对角线分出胜负

	for(int i = 0;i < 3;i++)
		for(int j = 0;j < 3;j++)
			if(board[i][j] == EMPTY)
				return GAME_UNFINISHED;//游戏还没结束

	return GAME_DRAW;//平局
}

void CGame::ChanegTurn()
{
	WHOSE_Turn = 
		(WHOSE_Turn==PLAYER_1_TURN)?PLAYER_2_TURN:PLAYER_1_TURN;
}

void CGame::StepBoard( int i,int j )
{
	board[i][j] = WHOSE_Turn==PLAYER_1_TURN?COLOR_1:COLOR_2;
	ChanegTurn();
}

void CGame::ClearLastStep( int i,int j )
{
	board[i][j] = EMPTY;
	ChanegTurn();
}

double GetScore(CGame game,BOOL IsPlayer1)
{
	double CurScore = 999999*(IsPlayer1 == game.WHOSE_Turn?-1:1);

	for(int i = 0;i < 3;i++)
	{
		for(int j = 0;j < 3;j++)
		{
			if (game.board[i][j] != EMPTY)
				continue;
			
			game.StepBoard(i,j);

			INT16 result = game.Judge();
			if(result == GAME_DRAW)
				return 0;
			else if(result == PLAYER_1_WIN)
				return IsPlayer1?1:-1;
			else if(result == PLAYER_2_WIN)
				return IsPlayer1?-1:1;

			double score = GetScore(game,IsPlayer1);
			game.ClearLastStep(i,j);
			if(IsPlayer1 == game.WHOSE_Turn && score > CurScore)
				CurScore = score;
			else if(IsPlayer1 != game.WHOSE_Turn && score < CurScore)
				CurScore = score;
		}
	}

	return CurScore;
}

void MinMax(CGame game,BOOL IsPlayer1)
{
	for(int i = 0;i < 3;i++)
	{
		for(int j = 0;j < 3;j++)
		{
			if (game.board[i][j] != EMPTY)
				continue;
			
			game.StepBoard(i,j);
			DrawResult(i,j,GetScore(game,IsPlayer1));
			game.ClearLastStep(i,j);
		}
	}
}

void InitGame(CGame &game)
{
	for(int i = 0;i < 3;i++)
	{
		for(int j = 0;j < 3;j++)
		{
			game.board[i][j] = EMPTY;
		}
	}
}

int main(int argc,char* argv[])
{
	CGame game;
	InitGame(game);
	InitImage();
	
	game.board[1][1] = COLOR_1;
	PutText(1,1,"1",cvScalar(255,0,0));
	game.WHOSE_Turn = PLAYER_2_TURN;

	MinMax(game,0);

	cout<<"X：必败\n-：平局\n！：获胜";
	cvShowImage("井",img);
	cvWaitKey(0);

	return 0;
}