LaTeX写算法伪码，需要包含包：

\usepackage{algorithm}

\usepackage{algpseudocode}

有些用例里还会加上：

\usepackage{caption}

\usepackage{algorithmicx}

可以遇到具体情形，再添加~

以常用的Levenberg-Marquardt(L-M)优化方法为例，给出一种方法：

\documentclass{article}

\usepackage{algorithm}

\usepackage{algpseudocode}

%\usepackage{caption}

%\usepackage{algorithmicx}

\begin{document}    

    \begin{algorithm}

		\caption{\textbf{Levenberg-Marquardt Method}}

		\label{Alg:scanMatching}

		\begin{algorithmic}[1]

			\Require

			$k:= 0$ ; $\nu:=2$; $\mathbf{x}:=\mathbf{x}_0 $;

			$\mathbf{A}:= \mathbf{J}(\mathbf{x})^T\mathbf{J}(\mathbf{x})$;

			$\mathbf{g}:=\mathbf{J}(\mathbf{x})^T\mathbf{f}(\mathbf{x})$

			\Ensure $found := (\| \mathbf{g}\|_\infty \leq \varepsilon_1)$; $\mu := \tau\cdot max\{ a_{ii} \}$

			\State \textbf{while} (\textbf{not} $found $) $\textbf{and}$ $k \leq k_{max}$ $\textbf{do}$

			\State \ \ \ \ $k := k+1$; Solve $(\mathbf{A}+\mu\mathbf{I})\mathbf{h}_{lm}) = -\mathbf{g}$

			\State \ \ \ \ $\textbf{if} \ \ \|\mathbf{h}_{lm} \| \leq \varepsilon_2 (\|\mathbf{x} + \varepsilon_2)$

			\State \ \ \ \ \ \ \ \  $found:= \textbf{true}$

			\State \ \ \ \ $\textbf{else}$

			\State \ \ \ \ \ \ \ \ $\mathbf{x}_{new} := \mathbf{x} + \mathbf{h}_{lm}$

			\State \ \ \ \ \ \ \ \ $\varrho:= (F(\mathbf{x}) - F(\mathbf{x}_{new}))/(L(\mathbf{0}) - L(\mathbf{h}_{lm}))$

			\State \ \ \ \ \ \ \ \ $\textbf{if} \ \  \varrho > 0$

			\State \ \ \ \ \ \ \ \ \ \ \ \ $\mathbf{x}:= \mathbf{x}_{new}$

			\State \ \ \ \ \ \ \ \ \ \ \ \ $\mathbf{A} := \mathbf{J}(\mathbf{x})^T\mathbf{J}(\mathbf{x}); \ \ \mathbf{g}:=\mathbf{J}(\mathbf{x})^T\mathbf{f}(\mathbf{x})$

			\State \ \ \ \ \ \ \ \ \ \ \ \ $found := (\|\mathbf{g}\|_{\infty} \leq \varepsilon_1)$

			\State \ \ \ \ \ \ \ \ \ \ \ \ $\mu := \mu \cdot max\{ \frac{1}{3}, 1-(2\varrho-1)^3\}; \ \ \nu:=2$

			\State \ \ \ \ \ \ \ \ $\textbf{else}$

			\State \ \ \ \ \ \ \ \ \ \ \ \ $\mu := \mu \cdot \nu; \ \ \nu := 2\nu$

			\State \ \ \ \ \ \ \ \ $\textbf{end if}$

			\State \ \ \ \ $\textbf{end if}$

			\State \textbf{end while}

		\end{algorithmic}

	\end{algorithm}

\end{document}

编译结果为：