为什么 cleveref 没有从 pseudo+tcolorbox 捕获浮点数？

Question

我正在切换到 来pseudo展示我的算法。按照文档，我将其与 结合起来tcolorbox创建了一个名为 的浮动环境algorithm。

但是当我想使用\creffromcleveref包引用它时，该命令无法捕获与其相关的浮动环境。因此我得到了?? 1而不是alg: 1（或类似的东西）。

以下是 MWE：

\documentclass{article} 

\usepackage{tcolorbox} % colored box with a lot of flexibility
    \tcbuselibrary{skins,theorems} % extra lib for pseudo

\usepackage{pseudo} % for pseudocode
    \newtcbtheorem{algorithm}{Algorithm}{pseudo/booktabs, float}{alg} % create a float env for algorithms

\usepackage{cleveref}

\begin{document} 

\begin{algorithm}{Euclid’s algorithm, \pr{Euclid}(a, b)}{euclid}
    \textbf{Input:}  Two positive integers, $a$ and $b$.\\
    \textbf{Output:} The greatest common divisor of $a$ and $b$.
    \begin{pseudo}[label=\small\arabic*, indent-mark]
        while $a \neq b$ \ct{If equal, both are gcd} \\+
            if $a > b$ \ct{ Reduce max with multiple of min} \\+
                    $a = a - b$ \ct{ $a$ is largest} \\-
            else $b = b - a$ \ct{ $b$ is largest} \\-
        return $a$ \ct{ Both are gcd, so return one}
    \end{pseudo}
    The running time is quadratic in the number of bits in the input.
\end{algorithm}

A sentence with a clever reference \cref{alg:euclid}.

\end{document}

我该如何解决这个问题？

Answer 1

只需使用以下命令设置新 tcolorbox 的标签类型label type=algorithm：

\documentclass{article}

\usepackage{tcolorbox} % colored box with a lot of flexibility
\tcbuselibrary{skins,theorems} % extra lib for pseudo

\usepackage{pseudo} % for pseudocode

\usepackage{cleveref}

\newtcbtheorem{algorithm}{Algorithm}{label type=algorithm,pseudo/booktabs, float}{alg} % create a float env for algorithms

\begin{document}

\begin{algorithm}{Euclid’s algorithm, \pr{Euclid}(a, b)}{euclid}
    \textbf{Input:}  Two positive integers, $a$ and $b$.\\
    \textbf{Output:} The greatest common divisor of $a$ and $b$.
    \begin{pseudo}[label=\small\arabic*, indent-mark]
        while $a \neq b$ \ct{If equal, both are gcd} \\+
            if $a > b$ \ct{ Reduce max with multiple of min} \\+
                    $a = a - b$ \ct{ $a$ is largest} \\-
            else $b = b - a$ \ct{ $b$ is largest} \\-
        return $a$ \ct{ Both are gcd, so return one}
    \end{pseudo}
    The running time is quadratic in the number of bits in the input.
\end{algorithm}

A sentence with a clever reference \cref{alg:euclid}.

\end{document}

这比@egreg 建议的设置内部 tcb 计数器稍微好一些/容易一些\crefname，因为您不需要处理内部计数器名称，而且它已经处理了\Crefname，这取决于您的 caps 选项。

或者，如果您愿意或需要设置crefname，您可以使用的相应选项进行设置tcolorbox（这几乎是来自pseudo的用户手册的示例）：

\documentclass{article}

\usepackage{tcolorbox} % colored box with a lot of flexibility
\tcbuselibrary{skins,theorems} % extra lib for pseudo

\usepackage{pseudo} % for pseudocode

\usepackage{cleveref}

\newtcbtheorem[crefname = {algorithm}{algorithms}]{algorithm}{Algorithm}{pseudo/booktabs, float}{alg} % create a float env for algorithms

\begin{document}

\begin{algorithm}{Euclid’s algorithm, \pr{Euclid}(a, b)}{euclid}
    \textbf{Input:}  Two positive integers, $a$ and $b$.\\
    \textbf{Output:} The greatest common divisor of $a$ and $b$.
    \begin{pseudo}[label=\small\arabic*, indent-mark]
        while $a \neq b$ \ct{If equal, both are gcd} \\+
            if $a > b$ \ct{ Reduce max with multiple of min} \\+
                    $a = a - b$ \ct{ $a$ is largest} \\-
            else $b = b - a$ \ct{ $b$ is largest} \\-
        return $a$ \ct{ Both are gcd, so return one}
    \end{pseudo}
    The running time is quadratic in the number of bits in the input.
\end{algorithm}

A sentence with a clever reference \cref{alg:euclid}.

\end{document}

就其效果而言，这严格等同于@egreg 的回答，只是您不需要知道/担心计数器的内部名称tcolorbox。

Answer 2

你收到警告

LaTeX Warning: cref reference format for label type `tcb@cnt@algorithm' 
undefined on input line 26.

定义格式。

并且，如果您不想让读者的眼睛刺痛，请不要在开括号后（或闭括号前）留空格。

\documentclass{article} 

\usepackage{tcolorbox} % colored box with a lot of flexibility
\tcbuselibrary{skins,theorems} % extra lib for pseudo
\usepackage{pseudo} % for pseudocode
\usepackage{cleveref}


% create a float env for algorithms
\newtcbtheorem{algorithm}{Algorithm}{pseudo/booktabs, float}{alg}

\crefname{tcb@cnt@algorithm}{algorithm}{algorithms}

\begin{document} 

\begin{algorithm}{Euclid’s algorithm, \pr{Euclid}(a, b)}{euclid}
    \textbf{Input:}  Two positive integers, $a$ and $b$.\\
    \textbf{Output:} The greatest common divisor of $a$ and $b$.
    \begin{pseudo}[label=\small\arabic*, indent-mark]
        while $a \neq b$ \ct{If equal, both are gcd} \\+
            if $a > b$ \ct{Reduce max with multiple of min} \\+
                    $a = a - b$ \ct{$a$ is largest} \\-
            else $b = b - a$ \ct{$b$ is largest} \\-
        return $a$ \ct{Both are gcd, so return one}
    \end{pseudo}
    The running time is quadratic in the number of bits in the input.
\end{algorithm}

A sentence with a clever reference to \cref{alg:euclid}.

\end{document}