Add en dash after numbering in list of algorithms

Question

I want to change the layout of the list of algorithms provided by algorithm2e from this

1 Sorting...........................15

to this

Algorithm 1 -- Sorting..............15

I was already able to add the "Algorithm" word by following the instructions in this answer, but could not get the en dash to appear. I tried to renew the \numberline to add the en dash, but the results weren't satisfactory. I know the memoir class has the \cftfigureaftersnum for inserting text after the figure numbers in the LOF and the \cfttableaftersnum as the equivalent for tables, but I could not find an equivalent for algorithms.

Any thoughts on this?

EDIT: I am giving support to the LaTeX class from my university, which is based on memoir. It uses algorithm2e as the default package for creating algorithms and does not use tocloft.

Answer 1

A native way of setting the LoA entries within memoir (or default classes loading tocloft) is to make each entry mimic the style of the LoF. This is easily achieved by adding

\makeatletter
\let\l@algocf\l@figure
\makeatother

to the document preamble. Now the regular \cftX... macros can by used:

\documentclass{memoir}

\usepackage{algorithm2e}

\makeatletter
\let\l@algocf\l@figure% Handle LoA exactly like LoF
\makeatother

\let\oldlistofalgorithms\listofalgorithms
\renewcommand{\listofalgorithms}{{%
  % Locally update LoA entries as they are now similar to LoF
  \renewcommand{\cftfigurepresnum}[1]{\gdef\algonum{##1}}% Grab algorithm number
  \renewcommand{\cftfigureaftersnumb}{Algorithm~\algonum~--~}%
  \setlength{\cftfigurenumwidth}{0pt}%
  \oldlistofalgorithms
}}

\begin{document}

\listofalgorithms

\begin{algorithm}
  \caption{An algorithm}
\end{algorithm}

\end{document}

Answer 2

There is no native support for algorithm2e in memoir (or the default document classes, even under the addition of tocloft). However, you can modify the LoA entry setter - \l@algocf - quite readily:

\documentclass{memoir}

\usepackage{algorithm2e}

\let\oldlistofalgorithms\listofalgorithms
\let\oldnumberline\numberline% Store \numberline
\newcommand{\algnumberline}[1]{Algorithm~#1 -- }
\renewcommand{\listofalgorithms}{%
  \let\numberline\algnumberline% Update \numberline
  \oldlistofalgorithms
  \let\numberline\oldnumberline% Restore \numberline
}

\begin{document}

\listofalgorithms

\begin{algorithm}
  \caption{An algorithm}
\end{algorithm}

\end{document}

If you wish to remove the indent of the LoA entries, also add the following:

\makeatletter
% https://tex.stackexchange.com/a/334060/5764
\renewcommand{\l@algocf}{\@dottedtocline{1}{0pt}{2.3em}}% Remove indent of algorithm in LoA
\makeatother