How to write a "repeat n times" loop in algorithmic?

Question

In algorithmic, I would like to write a loop that will look like the following:

   repeat $n$ times:
      [command]
   end

I found this question, explaining how to do this in algorithms2e, but it does not work with algorithmic.

EDIT: This is what I do now:

\documentclass{article}
\usepackage{algorithm}
\usepackage{algorithmic}
\begin{document}
\begin{algorithmic}[1] 
    \WHILE{Repeated at most $T$ times}
    \STATE Do Stuff
    \ENDWHILE
\end{algorithmic}
\end{document}

Please provide a full MWE (showing an algorithm with a normal loop for example that you want to change into a repeat n loop), expecially for pseudocode questions it is important to be very clear about the setup. — Marijn, Feb 15 '23 at 11:58
We need something that can be compiled on https://texlive.net/run . ;-) — projetmbc, Feb 15 '23 at 12:08
@ErelSegal-Halevi as projetmbc mentioned, this code is not compilable. Please add the documentclass and packages, begin/end document, and anything else needed to actually compile the code. Then we can be sure that we have the exact same setup as you, which guarantees that a solution also works for you. Moreover, it saves time for people trying to answer if they don't have to add boilerplate code themselves. — Marijn, Feb 15 '23 at 12:12

DG' · Accepted Answer · 2023-02-16T10:06:11.663

3

You can define a new block using algpseudocode: \RepeatN:

\documentclass{article}
\usepackage{algpseudocode}
\usepackage{algorithm}
\begin{document}
\algdef{SE}[REPEATN]{RepeatN}{End}[1]{\algorithmicrepeat\ #1 \textbf{times}}{\algorithmicend}
\begin{algorithmic}
    \RepeatN{$n$}
    \State Do stuff
    \End
\end{algorithmic}
\end{document}

For backwards compatibility with algorithmic you can use algcompatible:

\documentclass{article}
\usepackage{algcompatible}
\usepackage{algorithm}
\begin{document}
\algdef{SE}[REPEATN]{REPEATN}{END}[1]{\algorithmicrepeat\ #1 \textbf{times}}{\algorithmicend}
\begin{algorithmic}
    \REPEATN{$n$}
    \STATE Do stuff
    \END
\end{algorithmic}
\end{document}

edited Feb 16 '23 at 10:06

answered Feb 15 '23 at 12:48

DG'

21,727

This solution uses algpseudocode, but the project I work on uses algorithmic. When I add \usepacakge{algpseudocode} I get \algorithmic already defined. If I remove algorithmic, then some other parts of the code (e.g. \STATE) stop working. – Erel Segal-Halevi Feb 16 '23 at 09:22
algpseudocode is a layout for algorithmicx which is a more customizable replacement of algorithmic. The main difference is that only the first letter of the command is capitalized... – DG' Feb 16 '23 at 09:50
@ErelSegal-Halevi this illustrates the importance of a full compilable MWE, now you got an answer that you can't easily use because you didn't add your exact setup to your question at first. – Marijn Feb 16 '23 at 09:58
@Marijn You are right. I did not know that there are two versions of algorithmic in two different packages. – Erel Segal-Halevi Feb 16 '23 at 10:02
1

I added a version that is backwards compatible to algorithmic – DG' Feb 16 '23 at 10:06

score 3 · Answer 2 · answered Feb 16 '23 at 12:26

For comparison a version that uses only the internals of the algorithmic package:

\documentclass{article}
\usepackage{algorithm}
\usepackage{algorithmic}
\makeatletter
\newcommand{\REPEATN}[1]{\ALC@it\algorithmicrepeat%
\ #1 \textbf{times}\begin{ALC@rpt}}%
\newcommand{\ENDREPEAT}{\end{ALC@rpt}\ALC@it\algorithmicend}%
\makeatother
\begin{document}
\begin{algorithmic}[1] 
    \WHILE{Repeated at most $T$ times}
    \STATE Do Stuff
    \ENDWHILE
    \REPEATN{$n$}
    \STATE Do Stuff
    \ENDREPEAT
\end{algorithmic}
\end{document}

You can see that the solution of DG' with algcompatible is easier to use.

How to write a "repeat n times" loop in algorithmic?

2 Answers2