\documentclass{article}
\usepackage[pdftex,active,tightpage]{preview}
\setlength\PreviewBorder{2mm}

\usepackage[utf8]{inputenc} % this is needed for umlauts
\usepackage[ngerman]{babel} % this is needed for umlauts
\usepackage[T1]{fontenc}    % this is needed for correct output of umlauts in pdf
\usepackage{amssymb,amsmath,amsfonts} % nice math rendering
\usepackage{braket} % needed for \Set
\usepackage{algorithm,algpseudocode}

\begin{document}
\begin{preview}
    \begin{algorithm}[H]
        \begin{algorithmic}
            \Function{WER}{Reference $r$, Hypophysis $h$}
                \State int[$|r|+1$][$|h|+1$] $D$ \Comment{Initialisation}
                \For{($i=0$; $\;i \leq |r|$; $\;i$++)}
                    \For{($j=0$; $\;j \leq |h|$; $\;j$++)}
                        \If{$i==0$}
                            \State $D[0][j] \gets j$
                        \ElsIf{$j==0$}
                            \State $D[i][0] \gets i$
                        \EndIf
                    \EndFor
                \EndFor

                \State
                \For{($i=1$; $\;i \leq |r|$; $\;i$++)} \Comment{Calculation}
                    \For{($j=1$; $\;j \leq |h|$; $\;j$++)}
                        \If{$r[i-1] == h[j-1]$}
                            \State $D[i][j] \gets D[i-1][j-1]$
                        \Else
                            \State $sub \gets D[i-1][j-1] + 1$
                            \State $ins \gets D[i][j-1] + 1$
                            \State $del \gets D[i-1][j] + 1$
                            \State $D[i][j] \gets \min(sub, ins, del)$
                        \EndIf
                    \EndFor
                \EndFor

                \State
                \State \Return $D[|r|][|h|]$
            \EndFunction
        \end{algorithmic}
    \caption{Calculation of WER with Levenshtein distance}
    \label{alg:seq1}
    \end{algorithm}
\end{preview}
\end{document}