Drawing dashed multicolumn table

Question

I want to draw a multicolumn table, such that for every row, the second and third columns are divided into two parts, and there is a dashed line separating the two parts. Currently, I have something like this:

\documentclass[a4paper]{paper}

\usepackage{multirow}
\usepackage{makecell}
\usepackage{arydshln}

\begin{document}

\begin{table}[h]
\centering
\begin{tabular}{|*{7}{c|}}
\hline
\multirowcell{2}{Function} & \multicolumn{1}{c|}{Input(s)} & \multicolumn{1}{c|}{Output(s)} & \multicolumn{4}{c|}{Operations} \\
\cdashline{2-3} \cline{4-7}
& Type(s) & Type(s) & M & S & a & I \\
\hline
$\mathtt{j\_inv}$ & $(A, C)$ \\ $K \times K$ & $j(E)$ \\ $K$ & 3 & 4 & 8 & 1 \\ \hline
\end{tabular}
\caption{Summary of functions}
\label{tab:functions}
\end{table}

\end{document}

The point is that the table header is exactly as I want, but then in the second row when I start to actually write the values, I do not know how to make the second and third column divided into two parts like their header, and divided by a dashed line. Simply, I put the newline symbol between the two parts, but it does not give the desired effect of course. Any ideas how to achieve what I want?

Answer 1

Most likely I am missing something. You have already found out in the header how to split a cell. Why can't you just repeat it?

\documentclass[a4paper]{paper}

\usepackage{multirow}
\usepackage{makecell}
\usepackage{arydshln}

\begin{document}

\begin{table}[h]
\centering
\begin{tabular}{|*{7}{c|}}
\hline
\multirowcell{2}{Function} & \multicolumn{1}{c|}{Input(s)} & \multicolumn{1}{c|}{Output(s)} & \multicolumn{4}{c|}{Operations} \\
\cdashline{2-3} \cline{4-7}
& Type(s) & Type(s) & M & S & a & I \\
\hline
\multirowcell{2}{$\mathtt{j\_inv}$} & $(A, C)$ &
$K \times K$ & $j(E)$ & & &\\ 
\cdashline{2-3} \cline{4-7}
& $K$ & 3 & 4 & 8 & 1 &\\ 
\hline
\end{tabular}
\caption{Summary of functions}
\label{tab:functions}
\end{table}

\end{document}

If this is not the output you want, you may benefit from posting an annotated table in which you explain what you want to achieve.