C++ GoBoard::IsColor方法代码示例

bool GoEyeUtil::IsSinglePointEye2(const GoBoard& board, SgPoint p, 
                                  SgBlackWhite color, SgVector<SgPoint>& eyes)
{
    // Must be an empty point
    if (! board.IsColor(p, SG_EMPTY))
        return false;
    // All adjacent neighbours must be friendly
    SgBoardColor opp = SgOppBW(color);
    for (SgNb4Iterator adj(p); adj; ++adj)
    {
        SgBoardColor adjColor = board.GetColor(*adj);
        if (adjColor == opp || adjColor == SG_EMPTY)
            return false;
    }
    // All diagonals (with up to one exception) must be friendly or an eye
    int baddiags = 0;
    int maxbaddiags = (board.Line(p) == 1 ? 0 : 1);
    for (SgNb4DiagIterator it(p); it; ++it)
    {
        if (board.IsColor(*it, opp))
            ++baddiags;
        if (board.IsColor(*it, SG_EMPTY) && ! eyes.Contains(*it))
        {
            // Assume this point is an eye and recurse
            eyes.PushBack(p);
            if (! IsSinglePointEye2(board, *it, color, eyes))
                ++baddiags;
            eyes.PopBack();
        }
        if (baddiags > maxbaddiags)
            return false;
    }
    return true;
}

void GoInfluence::ComputeInfluence(const GoBoard& bd,
                      const SgBWSet& stopPts,
                      SgBWArray<SgPointArray<int> >* influence)
{
    const int MAX_INFLUENCE = 64;
    for (SgBWIterator it; it; ++it)
    {
        SgBlackWhite color = *it;
        ((*influence)[color]).Fill(0);
        for (GoBoard::Iterator it(bd); it; ++it)
        {
            SgPoint p(*it);
            if (bd.IsColor(p, color))
                Spread(bd, p, stopPts[color], MAX_INFLUENCE, 
                       (*influence)[color]);
        }
    }
}

bool GoEyeUtil::NumberOfMoveToEye2(const GoBoard& board, SgBlackWhite color,
                                   SgPoint p, int& nummoves)
{
    nummoves = 0;
    bool capturing = false;
    SgVector<SgPoint> usedpoints;
    usedpoints.PushBack(p);
    SgPointSet counted;

    // Can never turn own stone into an eye
    if (board.IsColor(p, color))
        return false;
    
    // If opponent stone then it must be captured to make eye
    if (board.IsColor(p, SgOppBW(color)))
    {
        capturing = true;
    
        // If it is obviously safe then it can never be an eye
        if (SinglePointSafe2(board, p)) // Quick, naive safety test
            return false;

        for (GoBoard::LibertyIterator libit(board, p); libit; ++libit)
            counted.Include(*libit);
    }

    // Count immediate adjacencies
    for (SgNb4Iterator nb(p); nb; ++nb)
    {
        SgPoint adj = *nb;
        
        // Empty points must be filled
        if (board.IsColor(adj, SG_EMPTY))
        {
            counted.Include(adj);
        }
        
        // If adjacent opponent then can never be an eye
        else if (board.IsColor(adj, SgOppBW(color)))
        {
            if (capturing)
                counted.Include(adj); // must capture and then fill
            else
                return false;
        }
    }

    // Up to one diagonal can be ignored: estimate most costly
    SgPoint toignore = SG_NULLPOINT;
    int maxcost = 0;
    int infcost = 1000;
    if (board.Line(p) > 1)
    {
        for (SgNb4DiagIterator nbd(p); nbd; ++nbd)
        {
            SgPoint diag = *nbd;
            int cost = 0;

            if (  board.IsColor(diag, SG_EMPTY)
               && ! IsSinglePointEye2(board, diag, color, usedpoints))
            {
                cost = 1;
            }
            
            else if (board.IsColor(diag, SgOppBW(color)))
            {
                // quick safety test
                if (SinglePointSafe2(board, diag))
                    cost = infcost;
                else
                    cost = board.NumLiberties(diag);
            }

            if (cost > maxcost)
            {
                maxcost = cost;
                toignore = diag;
            }
        }
    }

    // Now mark points that must be played to secure diagonals
    for (SgNb4DiagIterator nbd(p); nbd; ++nbd)
    {
        SgPoint diag = *nbd;
        if (diag == toignore)
            continue;
        
        // Empty points must be filled (unless they are eyes)
        if (  board.IsColor(diag, SG_EMPTY)
           && ! IsSinglePointEye2(board, diag, color, usedpoints))
        {
            counted.Include(diag);
        }
        
        // Opponent stones on diagonals must be captured and filled
        else if (board.IsColor(diag, SgOppBW(color)))
        {
            if (SinglePointSafe2(board, diag))
                return false;
//.........这里部分代码省略.........