latex config for assignment

assignment.sty

%!TEX encoding = UTF-8 Unicode

\documentclass[a4paper,parskip,DIV15]{scrartcl}
\usepackage[utf8]{inputenc}
% \usepackage[utf8x]{inputenc}
\usepackage[ngerman]{babel}

% pretty fonts
\usepackage[T1]{fontenc}
\usepackage[defaultsans, scale=0.9]{lato}
\usepackage[bitstream-charter]{mathdesign}

% hyperrefs
\usepackage[colorlinks=false, pdfborder={0 0 0}]{hyperref}

\usepackage{enumerate}
\usepackage{epsdice}

% listings
\usepackage{color}
\usepackage{listings}
\definecolor{keyword}      {rgb}{0.7, 0.3, 0.2}
\definecolor{comment}      {rgb}{0.4, 0.7, 0.7}
\definecolor{string}       {rgb}{0.0, 0.7, 0.3}
\definecolor{line_numbers} {rgb}{0.9, 0.9, 0.9}
\definecolor{identifier}   {rgb}{0.1, 0.1, 0.5}
\lstset{
    showspaces=false, 
    showstringspaces=false,
    basicstyle=\ttfamily\footnotesize,
    keywordstyle=\color{keyword}, 
    commentstyle=\itshape\color{comment}, 
    stringstyle=\color{string},
	identifierstyle=\color{identifier},
    numbers=left, 
    numberstyle=\color{line_numbers}, 
    stepnumber=1, 
    numbersep=10pt,
    breaklines=true,
	literate={ö}{{\"o}}1
	           {ä}{{\"a}}1
	           {ü}{{\"u}}1
	           {ß}{{\ss}}1
}

% math packages
\usepackage[fleqn]{mathtools}
\usepackage{xfrac}

% math shortcuts
\newcommand{\impl}{\Longrightarrow}
\newcommand{\tx}[1]{\text{#1} \:\:}
\newcommand{\Z}{\mathbb{Z}}
\newcommand{\N}{\mathbb{N}}
\newcommand{\R}{\mathbb{R}}
\newcommand{\C}{\mathbb{C}}
\newcommand{\Poly}{\mathfrak{P}}
\newcommand{\dx}{\: \mathrm{d}x}
\newcommand{\dt}{\: \mathrm{d}t}
\newcommand{\e}{\mathrm e}
\renewcommand{\i}{\mathrm i}
\DeclarePairedDelimiter\abs{\lvert}{\rvert}
\DeclarePairedDelimiter\norm{\lVert}{\rVert}

\usepackage{titlesec}
\setcounter{secnumdepth}{4}
\renewcommand{\thesection}{Aufgabe \arabic{section}: }
\renewcommand{\thesubsection}{\arabic{section}\alph{subsection})}
\renewcommand{\theparagraph}{\arabic{section}\alph{paragraph})}
\newcommand{\exercise}[1]{\section{#1}}
\newcommand{\subexercise}[1]{\subsection{#1}}

\usepackage{fancyvrb}
\newenvironment{preformatted}{
	% \vspace-\baselineskip
	% \footnotesize
	\begin{Verbatim}
}{
	\end{Verbatim}
	% \normalsize
}

% set width for every column type
\usepackage{tabularx}
\newcolumntype{L}[1]{>{\raggedright\arraybackslash}p{#1}} % linksbündig mit Breitenangabe
\newcolumntype{C}[1]{>{\centering\arraybackslash}p{#1}} % zentriert mit Breitenangabe
\newcolumntype{R}[1]{>{\raggedleft\arraybackslash}p{#1}} % rechtsbündig mit Breitenangabe