private int[][] copyBoard() {
        int[][] newBoard = new int[puzzuleBoard.length][puzzuleBoard[0].length];
        for ( int i = 0 ; i < newBoard.length ; i ++ ) {
            int[] copiedLine = Arrays.copyOf(puzzuleBoard[i], puzzuleBoard[i].length);
            newBoard[i] = copiedLine;
        }

        return newBoard;
    }