Question

我正在写国际象棋程序，我有一个名为Pieces的抽象类。我通过使用指针在我的主类中使用这个抽象类，如：Pieces * newset = currentboard[][];

如果我在这个棋盘上移动，那么移动实际上就是这样。我想分析电路板的当前状态，从而创建电路板的副本。我怎么做？

我的Piece课程样本以及我正在做的事情如下。

class Piece
{
  public:
    Piece(char cColor) : mcColor(cColor) {}
    ~Piece() {}
    virtual char GetPiece() = 0;
    virtual int GetValue() = 0;
    virtual int GetPieceActionValue() = 0;
    char GetColor() {
        return mcColor;
    }
    bool IsLegalMove(int CurrentRow, int CurrentCol, int DestRow, int DestCol, Piece* NewBoard[8][8]) {
        Piece* qpDest = NewBoard[DestRow][DestCol];
        if ((qpDest == 0) || (mcColor != qpDest->GetColor())) {
            return LegalSquares(CurrentRow, CurrentCol, DestRow, DestCol, NewBoard);
        }
        return false;
    }

  private:
    virtual bool LegalSquares(int CurrentRow, int CurrentCol, int DestRow, int DestCol, Piece* NewBoard[8][8]) = 0;
    char mcColor;
};

以下是派生类的示例：

class Bishop
{
  public:
    Bishop(char cColor) : Piece(cColor) {}
    ~Bishop() {}

  private:
    virtual char GetPiece() {
        return 'B';
    }
    virtual int GetValue() {
        return 325;
    }
    virtual int GetPieceActionValue() {
        return 3;
    }
    bool LegalSquares(int CurrentRow, int CurrentCol, int DestRow, int DestCol, Piece* NewBoard[8][8]) {
        if ((DestCol - CurrentCol == DestRow - CurrentRow) || (DestCol - CurrentCol == CurrentRow - DestRow)) {
            // Make sure that all invervening squares are empty
            int iRowOffset = (DestRow - CurrentRow > 0) ? 1 : -1;
            int iColOffset = (DestCol - CurrentCol > 0) ? 1 : -1;
            int iCheckRow;
            int iCheckCol;
            for (iCheckRow = CurrentRow + iRowOffset, iCheckCol = CurrentCol + iColOffset;
                iCheckRow !=  DestRow;
                iCheckRow = iCheckRow + iRowOffset, iCheckCol = iCheckCol + iColOffset)
            {
                if (NewBoard[iCheckRow][iCheckCol] != 0) {
                    return false;
                }
            }
            return true;
        }
        return false;
    }
};

使用班级进行移动：

if (qpCurrPiece->IsLegalMove(StartRow, StartCol, EndRow, EndCol, NewBoard)) {

  // Make the move
  Piece* qpTemp = NewBoard[EndRow][EndCol];
  NewBoard[EndRow][EndCol] = NewBoard[StartRow][StartCol];
  NewBoard[StartRow][StartCol] = 0;

  // Make sure that the current player is not in check
  if (!GameBoard.IsInCheck(mcPlayerTurn)) {
    delete qpTemp;
    bValidMove = true;
  } else { 

    // Undo the last move
    NewBoard[StartRow][StartCol] = NewBoard[EndRow][EndCol];
    NewBoard[EndRow][EndCol] = qpTemp;
  }
}

我希望能够在不使用指针的情况下引用此类，以便不对板进行永久性更改。

Answer 1

你需要为每个类提供一个虚拟Clone（）函数，对于Bishop看起来像：

Piece * Bishop :: Clone() {
     return new Bishop( * this );
}

现在从OldBoard克隆电路板，如：

Board newboard;   // assume board is 8x8 matrix of Piece *

for ( int i = 0; i < 8; i++ ) {
    for ( int j = 0; j < 8; j++ ) {
       newboard[i][j] = OldBoard[i][j]->Clone();
    }
}

Answer 2

你需要一个抽象的方法

 Piece *Piece::Duplicate()

然后在子类中实现它，即

 class Bishop {
   Bishop(const Bishop &b) { ... } // copy constructor
   Piece *Duplicate() { Bishop *n = new Bishop(*this); // calls copy constructor
     return n; }
 }

Answer 3

或者你可以写一个拷贝构造函数给Bishop类，它反过来实现一个深层拷贝，假设你的currentBoard是Bishop类的一个实例。

创建抽象类的克隆

3 个答案: