Some new changes

game.hpp

@@ -7,7 +7,32 @@ public:
     void start();
 
 private:
+    static const int SIZE = 4;
+    int board[SIZE][SIZE];
+    int score;
+
+    // Initialization
     void initBoard();
+    void addRandomTile();
+
+    // Movement
+    void moveLeft();
+    void moveRight();
+    void moveUp();
+    void moveDown();
+
+    // Helper functions
+    void transpose();
+    void reverseRow(int rowIndex);
+    void compressRow(int row[4]);
+    void mergeRow(int row[4]);
+
+    // Logic
+    bool checkGameOver();
+    bool hasEmptyCell();
+    bool canMerge();
+
+    // UI
     void printBoard();
 };