engine.cpp

Siemens 的SIMpad是一个多媒体设备

	      if (val > maxval)
		{
		  maxval = val;
		  max_x = x;
		  max_y = y;
		  number_of_maxval = 1;
		}
	      else if (val == maxval) number_of_maxval++;
	    }

	  if (GetInterrupt()) break;
	}

  // long endtime = times(&tmsdummy);

  if (number_of_maxval > 1)
    {
      int r = (rand() % number_of_maxval) + 1;

      int i;

      for (i=0; i < number_of_moves; i++)
	if (moves[i].m_value == maxval && --r <= 0) break;

      max_x = moves[i].m_x;
      max_y = moves[i].m_y;
    }

  if (GetInterrupt()) {       
    return Move(-1, -1, -1);
  } else if (maxval != -LARGEINT) {
    return Move(max_x, max_y, player);
  } else {
    return Move(-1, -1, -1);
  }
}


Move Engine::ComputeFirstMove(Game g) {
  int r;
  int player = g.GetWhoseTurn();

  r = (rand() % 4) + 1;

  if (player == Score::WHITE)
    {
      if (r == 1) return Move(3, 5, player);
      else if (r == 2) return  Move(4, 6, player);
      else if (r == 3) return  Move(5, 3, player);
      else return  Move(6, 4, player);
    }
  else
    {
      if (r == 1) return  Move(3, 4, player);
      else if (r == 2) return  Move(5, 6, player);
      else if (r == 3) return  Move(4, 3, player);
      else return  Move(6, 5, player);
    }
}


int Engine::ComputeMove2(int xplay, int yplay, int player, int level,
			 int cutoffval, ULONG64 playerbits, 
			 ULONG64 opponentbits)
{
  int number_of_turned = 0;
  SquareStackEntry mse;
  int opponent = Score::GetOpponent(player);

  m_nodes_searched++;

  m_board[xplay][yplay] = player;
  playerbits |= m_coord_bit[xplay][yplay];
  m_score.ScoreAdd(player, 1);
  m_bc_score.ScoreAdd(player, m_bc_board[xplay][yplay]);

  ///////////////////
  // Turn all pieces:
  ///////////////////

  for (int xinc=-1; xinc<=1; xinc++)
    for (int yinc=-1; yinc<=1; yinc++)
      if (xinc != 0 || yinc != 0)
	{
	  int x, y;

	  for (x = xplay+xinc, y = yplay+yinc; m_board[x][y] == opponent;
	       x += xinc, y += yinc)
	    ;

	  if (m_board[x][y] == player)
	    for (x -= xinc, y -= yinc; x != xplay || y != yplay;
		 x -= xinc, y -= yinc)
	      {
		m_board[x][y] = player;
		playerbits |= m_coord_bit[x][y];
		opponentbits &= ~m_coord_bit[x][y];
		m_squarestack.Push(x, y);
		m_bc_score.ScoreAdd(player, m_bc_board[x][y]);
		m_bc_score.ScoreSubtract(opponent, m_bc_board[x][y]);
		number_of_turned++;
	      }
	}

  int retval = -LARGEINT;

  if (number_of_turned > 0)
    {
      //////////////
      // Legal move:
      //////////////

      m_score.ScoreAdd(player, number_of_turned);
      m_score.ScoreSubtract(opponent, number_of_turned);

      if (level >= m_depth) retval = EvaluatePosition(player); // Terminal node
      else
	{
	  int maxval = TryAllMoves(opponent, level, cutoffval, opponentbits,
				   playerbits);

	  if (maxval != -LARGEINT) retval = -maxval;
	  else
	    {
	      ///////////////////////////////////////////////////////////////
	      // No possible move for the opponent, it is players turn again:
	      ///////////////////////////////////////////////////////////////
	      retval= TryAllMoves(player, level, -LARGEINT, playerbits,
				  opponentbits);

	      if (retval == -LARGEINT)
		{
		  ///////////////////////////////////////////////
		  // No possible move for anybody => end of game:
		  ///////////////////////////////////////////////

		  int finalscore =
		    m_score.GetScore(player) - m_score.GetScore(opponent);

		  if (m_exhaustive) retval = finalscore;
		  else
		    {
		      // Take a sure win and avoid a sure loss (may not be optimal):

		      if (finalscore > 0) retval = LARGEINT - 65 + finalscore;
		      else if (finalscore < 0) retval = -(LARGEINT - 65 + finalscore);
		      else retval = 0;
		    }
		}
	    }
	}

      m_score.ScoreAdd(opponent, number_of_turned);
      m_score.ScoreSubtract(player, number_of_turned);
    }

  /////////////////
  // Restore board:
  /////////////////

  for (int i = number_of_turned; i > 0; i--)
    {
      mse = m_squarestack.Pop();
      m_bc_score.ScoreAdd(opponent, m_bc_board[mse.m_x][mse.m_y]);
      m_bc_score.ScoreSubtract(player, m_bc_board[mse.m_x][mse.m_y]);
      m_board[mse.m_x][mse.m_y] = opponent;
    }

  m_board[xplay][yplay] = Score::NOBODY;
  m_score.ScoreSubtract(player, 1);
  m_bc_score.ScoreSubtract(player, m_bc_board[xplay][yplay]);

  if (number_of_turned < 1 || GetInterrupt()) return ILLEGAL_VALUE;
  else return retval;
}


int Engine::TryAllMoves(int opponent, int level, int cutoffval,
			ULONG64 opponentbits, ULONG64 playerbits)
{
  int maxval = -LARGEINT;

  // keep GUI alive
  yield();

  ULONG64 null_bits;
  null_bits = 0;

  for (int x=1; x<9; x++)
    {
      for (int y=1; y<9; y++)
	if (m_board[x][y] == Score::NOBODY &&
	    (m_neighbor_bits[x][y] & playerbits) != null_bits)
	  {
	    int val = ComputeMove2(x, y, opponent, level+1, maxval, opponentbits,
				   playerbits);

	    if (val != ILLEGAL_VALUE && val > maxval)
	      {
		maxval = val;
		if (maxval > -cutoffval || GetInterrupt()) break;
	      }
	  }

      if (maxval > -cutoffval || GetInterrupt()) break;
    }

  if (GetInterrupt()) return -LARGEINT;
  return maxval;
}


int Engine::EvaluatePosition(int player)
{
  int retval;

  int opponent = Score::GetOpponent(player);
  int score_player = m_score.GetScore(player);
  int score_opponent = m_score.GetScore(opponent);

  if (m_exhaustive) retval = score_player - score_opponent;
  else
    {
      retval = (100-m_coeff) *
	(m_score.GetScore(player) - m_score.GetScore(opponent)) +
	m_coeff * BC_WEIGHT *
	(m_bc_score.GetScore(player)-m_bc_score.GetScore(opponent));
    }

  return retval;
}


void Engine::SetupBits()
{
  //m_coord_bit = new long[9][9];
  //m_neighbor_bits = new long[9][9];

  ULONG64 bits = 1;

  for (int i=1; i < 9; i++)
    for (int j=1; j < 9; j++)
      {
	m_coord_bit[i][j] = bits;
#if !defined(__GNUC__)
	bits.shl();
#else
	bits *= 2;
#endif
      }

  for (int i=1; i < 9; i++)
    for (int j=1; j < 9; j++)
      {
	m_neighbor_bits[i][j] = 0;

	for (int xinc=-1; xinc<=1; xinc++)
	  for (int yinc=-1; yinc<=1; yinc++)
	    if (xinc != 0 || yinc != 0)
	      if (i + xinc > 0 && i + xinc < 9 && j + yinc > 0 && j + yinc < 9)
		m_neighbor_bits[i][j] |= m_coord_bit[i + xinc][j + yinc];
      }
}


void Engine::SetupBcBoard()
{
  // JAVA m_bc_board = new int[9][9];

  for (int i=1; i < 9; i++)
    for (int j=1; j < 9; j++)
      {
	if (i == 2 || i == 7) m_bc_board[i][j] = -2; else m_bc_board[i][j] = 0;
	if (j == 2 || j == 7) m_bc_board[i][j] -= 2;
      }

  m_bc_board[1][1] = 20;
  m_bc_board[8][1] = 20;
  m_bc_board[1][8] = 20;
  m_bc_board[8][8] = 20;

  m_bc_board[1][2] = -2;
  m_bc_board[2][1] = -2;
  m_bc_board[1][7] = -2;
  m_bc_board[7][1] = -2;
  m_bc_board[8][2] = -2;
  m_bc_board[2][8] = -2;
  m_bc_board[8][7] = -2;
  m_bc_board[7][8] = -2;
}


int Engine::CalcBcScore(int player)
{
  int sum = 0;

  for (int i=1; i < 9; i++)
    for (int j=1; j < 9; j++)
      if (m_board[i][j] == player) 
	sum += m_bc_board[i][j];

  return sum;
}


ULONG64 Engine::ComputeOccupiedBits(int player)
{
  ULONG64 retval = 0;

  for (int i=1; i < 9; i++)
    for (int j=1; j < 9; j++)
      if (m_board[i][j] == player) retval |= m_coord_bit[i][j];

  return retval;
}