[LaTeX] 如何写一个算法？

有时候论文里面需要写算法伪代码，所以这里记录下用LaTeX写一个算法的操作。如果想直接看效果，请直接翻到`3）输出算法效果`这一小节。

宇内虹游

12073人浏览 · 2019-10-30 09:47:13

宇内虹游 · 2019-10-30 09:47:13 发布

文章目录

前言

有时候论文里面需要写算法伪代码，所以这里记录下用LaTeX写一个算法的操作。如果想直接看效果，请直接翻到3）输出算法效果这一小节。

示例

1）第一步

首先在\begin{document}之前得加上：（看上去有点多？，没办法，这都是为了作出比较全，比较完善、好看的算法来）

%基本算法包
\usepackage{calligra}
\usepackage{algorithm}
\usepackage{algorithmicx}
\usepackage{algpseudocode} 
\usepackage{amsmath} 

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{algorithm}% http://ctan.org/pkg/algorithm
%\PassOptionsToPackage{noend}{algpseudocode}% comment out if want end's to show
\usepackage{algpseudocode}% http://ctan.org/pkg/algorithmicx

\errorcontextlines\maxdimen

% begin vertical rule patch for algorithmicx (http://tex.stackexchange.com/questions/144840/vertical-loop-block-lines-in-algorithmicx-with-noend-option)
\makeatletter
% start with some helper code
% This is the vertical rule that is inserted
\newcommand*{\algrule}[1][\algorithmicindent]{\makebox[#1][l]{\hspace*{.5em}\thealgruleextra\vrule height \thealgruleheight depth \thealgruledepth}}%
% its height and depth need to be adjustable
\newcommand*{\thealgruleextra}{}
\newcommand*{\thealgruleheight}{.75\baselineskip}
\newcommand*{\thealgruledepth}{.25\baselineskip}

\newcount\ALG@printindent@tempcnta
\def\ALG@printindent{%
	\ifnum \theALG@nested>0% is there anything to print
	\ifx\ALG@text\ALG@x@notext% is this an end group without any text?
	% do nothing
	\else
	\unskip
	\addvspace{-1pt}% FUDGE to make the rules line up
	% draw a rule for each indent level
	\ALG@printindent@tempcnta=1
	\loop
	\algrule[\csname ALG@ind@\the\ALG@printindent@tempcnta\endcsname]%
	\advance \ALG@printindent@tempcnta 1
	\ifnum \ALG@printindent@tempcnta<\numexpr\theALG@nested+1\relax% can't do <=, so add one to RHS and use < instead
	\repeat
	\fi
	\fi
}%
\usepackage{etoolbox}
% the following line injects our new indent handling code in place of the default spacing
\patchcmd{\ALG@doentity}{\noindent\hskip\ALG@tlm}{\ALG@printindent}{}{\errmessage{failed to patch}}
\makeatother

% the required height and depth are set by measuring the content to be shown
% this means that the content is processed twice
\newbox\statebox
\newcommand{\myState}[1]{%
	\setbox\statebox=\vbox{#1}%
	\edef\thealgruleheight{\dimexpr \the\ht\statebox+1pt\relax}%
	\edef\thealgruledepth{\dimexpr \the\dp\statebox+1pt\relax}%
	\ifdim\thealgruleheight<.75\baselineskip
	\def\thealgruleheight{\dimexpr .75\baselineskip+1pt\relax}%
	\fi
	\ifdim\thealgruledepth<.25\baselineskip
	\def\thealgruledepth{\dimexpr .25\baselineskip+1pt\relax}%
	\fi
	%\showboxdepth=100
	%\showboxbreadth=100
	%\showbox\statebox
	\State #1%
	%\State \usebox\statebox
	%\State \unvbox\statebox
	%reset in case the next command is not wrapped in \myState
	\def\thealgruleheight{\dimexpr .75\baselineskip+1pt\relax}%
	\def\thealgruledepth{\dimexpr .25\baselineskip+1pt\relax}%
}
% end vertical rule patch for algorithmicx

2）第二步

在正文添加如下代码：

\begin{algorithm}[ht!]  %ht!参数是调整算法在文章中的位置
	%	\renewcommand{\algorithmicrequire}{\textbf{Input  \ \ :}}  %这样的指令可以让output和input的‘:’号在同一竖线上。但没必要，所以我注释了
	\renewcommand{\algorithmicrequire}{\textbf{Input:}}
	\renewcommand{\algorithmicensure}{\textbf{Output:}}
	\caption{xxx标题}  
	\label{xxx标签}
	\begin{algorithmic}[1] %每行显示行号
		\Require Faulty program  ($\textit{P}$)
		\Require Test cases $\left(\textit{Tests}\right) $
		\Require xxx 
		\Require xxx %细节就不多说了，略之
		\Ensure  xxx 
		
		\Function{xxx}{xxx} \label{xxx1}
		\For{xxx} 
		\myState{xxx} 
		\State xxx
		\EndFor 
		\EndFunction \label{xxx2}
		
		\Statex   %算法中的空行
		
		\Function{main}{}
		\State xxx
		\Repeat
			\If{xxx}
				\State xxx
			\Else  \Comment{xxx}  %注释
				\State xxx
				\For{xxx} 
					\If{xxx}
						\State xxx
					\EndIf
				\EndFor
				\State xxx
			\EndIf
			
		   	\State xxx
			\If{xxx}
				\State xxx
			\EndIf
		\Until{xxx}
		\EndFunction
	\end{algorithmic}
\end{algorithm}