EssayproSolutions

         unsigned int blockdimx; // horizontal dimension of the list (in blocks)        unsigned int blockdimy; // vertical dimension of the list (in blocks)               /**         *  Deallocates any associated dynamic memory and sets private attributes appropriately         *         *  @post this list is empty         */        void Clear();
         /**         *  Copies the data and structure of otherlist into this list         *         *  @post this list is a physically separate copy of otherlist         */        void Copy(const TwoDLinkedList& otherlist);
     public:        /**         *  Default constructor creates an empty list         */        TwoDLinkedList();
         /**         *  Parameterized constructor creates a list with blockdimx columns,         *  blockdimy rows, using color data from img         *         *  @param img – input PNG         *  @param blockdimx – horizontal dimension of the list (in Blocks, i.e. number of columns)         *  @param blockdimy – vertical dimension of the list (in Blocks, i.e. number of rows)         *         *  @pre img has dimensions at least 1×1         *  @pre 1 <= blockdimx <= PNG's horizontal dimension (in pixels)         *  @pre 1 <= blockdimy <= PNG's vertical dimension (in pixels)         */        TwoDLinkedList(PNG& img, unsigned int blockdimx, unsigned int blockdimy);          /**         *  Copy constructor creates a new list as a copy of the data in otherlist         */        TwoDLinkedList(const TwoDLinkedList& otherlist);          /**         *  Overloaded assignment operator assigns structure and data of rhs into this list         *         *  @post this list is a physically separate copy of otherlist         */        TwoDLinkedList& operator=(const TwoDLinkedList& rhs);          /**         *  Destructor deallocates associated dynamic memory         */        ~TwoDLinkedList();          /**         *  Builds the structure of this list from the provided parameters.         *  The dimension of individual blocks will be an even division         *  of the input PNG's dimensions by blockdimx or blockdimy.         *  Assume that supplied PNG dimensions will be divisible by         *  blockdimx and blockdimy.         *         *  @pre PNG horizontal dimension is divisible by blockdimx         *  @pre PNG vertical dimension is divisible by blockdimy         *         *  Example: PNG dimensions 320x240         *           blockdimx = 4         *           blockdimy = 2         *           The constructed list will have the following Block and node structure:         *         *                +-----------+     +-----------+     +-----------+     +-----------+         *  northwest --> |           | –> |           | –> |           | –> |           |         *                |  80 x 120 |     |  80 x 120 |     |  80 x 120 |     |  80 x 120 |         *                |           | <-- |           | <-- |           | <-- |           |         *                +-----------+     +-----------+     +-----------+     +-----------+         *                   |     ^           |     ^           |     ^           |     ^           *                   v     |           v     |           v     |           v     |           *                +-----------+     +-----------+     +-----------+     +-----------+         *                |           | --> |           | –> |           | –> |           |         *                |  80 x 120 |     |  80 x 120 |     |  80 x 120 |     |  80 x 120 |         *                |           | <-- |           | <-- |           | <-- |           | <-- southeast         *                +-----------+     +-----------+     +-----------+     +-----------+         */        void Build(PNG& img, unsigned int blockdimx, unsigned int blockdimy);          /**         *  Returns the horizontal dimension of this list (in blocks)         */        unsigned int GetBlockDimensionX() const;          /**         *  Returns the vertical dimension of this list (in blocks)         */        unsigned int GetBlockDimensionY() const;          /**         *  Places this lists's color data into a PNG of appropriate dimensions         *  @param scale - integer multiplier for dimensions. 0 = scale by 0.5.         */        PNG Render(unsigned int scale) const;          /**         *  Reorganizes the list and node contents so that a rendered image will be flipped horizontally.         *  This must be achieved by pointer manipulation. Do not deallocate any existing nodes, and         *  do not allocate any new nodes.         *         *  Ensure that the integrity of north/south/east/west pointers of all nodes is maintained.         *         *  You may use up to O(n) time and space complexity, where n is the total number of nodes in the list.         *         *  Example: A, B, C, D etc. are physical nodes (each at a particular address)         *  before:         *   northwest -> A <-> B <-> C <-> D         *                ^     ^     ^     ^         *                v     v     v     v         *                E <-> F <-> G <-> H         *                ^     ^     ^     ^         *                v     v     v     v         *                I <-> J <-> K <-> L  <- southeast         *         *  after:         *   northwest -> D <-> C <-> B <-> A         *                ^     ^     ^     ^         *                v     v     v     v         *                H <-> G <-> F <-> E         *                ^     ^     ^     ^         *                v     v     v     v         *                L <-> K <-> J <-> I  <- southeast         */        void FlipHorizontal();      private:        #include "twodlinkedlist-private.h"  }; #endif My question is why i had error: use of undeclared identifier 'blockdimx' and 'blockdimy'