如何在表格上方添加标题？

Question

我试图在表格上方添加标题，但没有成功。代码如下：

    \begin{table}[b]
      \centering
      \begin{tabular}{|c|c|c|c|}
      \cline{2-4}
      \multicolumn{1}{c|}{}& &{CPU time}&\\
      \cline{2-4}
      \multicolumn{1}{c|}{} & Algorithm 1  & Algorithm 2  & Algorithm 3\\
      \hline
      $n=29$                & $0.001137$   & $0.000962$   & $0.000679$\\
      \hline
      $n=97$                & $0.020917$   & $0.008182$   & $0.005571$\\
      \hline
      $n=353$               & $0.699906$   & $0.067613$   & $0.054980$\\
      \hline
      $n=1345$              & $32.03852$   & $1.063334$   & $0.823744$\\
      \hline
    \end{tabular}
    \caption{Caption}
    \label{time}
    \end{table}

如何更好地设置标题？谢谢！

我想要获得的是：

Answer 1

没有垂直线和对齐小数点分隔符的替代布局可以是

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage{booktabs,siunitx}
\begin{document}
\begin{table}[b]
\centering
\begin{tabular}{l S S S S }
\toprule
\multicolumn{1}{c}{} &     \multicolumn{3}{c}{\large CPU Time}          \\
                            & \multicolumn{1}{c}{Algorithm 1}  & \multicolumn{1}{c}{Algorithm 2}  & \multicolumn{1}{c}{Algorithm 3}\\
      \midrule
      $n=29$                & 0.001137   & 0.000962   & 0.000679 \\
      \midrule
      $n=97$                & 0.020917   & 0.008182   & 0.005571  \\
      \midrule
      $n=353$               & 0.699906   & 0.067613   & 0.054980  \\
      \midrule
      $n=1345$              & 32.03852   & 1.063334  & 0.823744  \\
\bottomrule
\end{tabular}
\caption{Caption\label{time}}
\end{table}
\end{document} 

使用siunitx和booktabs包

Answer 2

好的，你可以这样做

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage{booktabs}
\begin{document}
    \begin{table}[b]
      \centering
      \begin{tabular}{|c|c|c|c|}
      \cline{2-4}
      \multicolumn{1}{c}{}  & \multicolumn{3}{|c|}{CPU time}\\
      \cline{2-4}
      \multicolumn{1}{c|}{} & Algorithm 1  & Algorithm 2  & Algorithm 3\\
      \hline
      $n=29$                & $0.001137$   & $0.000962$   & $0.000679$\\
      \hline
      $n=97$                & $0.020917$   & $0.008182$   & $0.005571$\\
      \hline
      $n=353$               & $0.699906$   & $0.067613$   & $0.054980$\\
      \hline
      $n=1345$              & $32.03852$   & $1.063334$   & $0.823744$\\
      \hline
    \end{tabular}
    \caption{Caption}
    \label{time}
    \end{table}
\end{document} 

但布局看起来很丑。避免在表格中使用垂直线。