format two tables inside a figure

Question

I have a figure that contains two tables, I would like to give format to them.

What would be the best option?

{\footnotesize\begin{figure} [h!tb]
\centering
\begin{tabular} {l }
\hline
\textcolor{sql}{double} N;\\
\textcolor{sql}{double}[] L;\\
\textcolor{sql}{double}[,] Q;\\
\textcolor{sql}{int} d;\\
\textcolor{sql}{double}[,]rho;\\
\textcolor{sql}{public} NLQ(\textcolor{sql}{int} dimension) \{ \\
~~d    = dimension;\\
~~N    = 0.0;\\
~~L    = new \textcolor{sql}{double}[d];\\
~~Q   = new \textcolor{sql}{double}[d, d];\\
\} \\
\hline
\end{tabular}
\begin{tabular} {l }
\hline
\textbf{in}:   $record$, $d$  \\
1 :$n$ += 1\\
2: \textcolor{sql}{For} i=0 to d\\
3: ~~~~$L_i$ += $record_i$\\
4: ~~~~\textcolor{sql}{For} j=0 to i\\
5: ~~~~~~~~$Q_{i,j}$=$Q_{j,i}$= $record_i$*$record_j$ \\
6:~~~~~\textcolor{sql}{End}\\
7:\textcolor{sql}{End}\\
\textbf{out:}  $n$, $L$, $Q$ \\
\hline
\end{tabular}
\caption{NLQ Definition  and Reader Function}
\label{fig:implementNLQ}
\end{figure}
}

maybe something like this

by the way I am using:

\definecolor{sql}{rgb}{0,0,2.55}
\definecolor{sqlC}{rgb}{0,0.44,0}
\definecolor{BRICKRED}{rgb}{0.57,0.0,0.0}
\definecolor{FORESTGREEN}{rgb}{0.0,0.34,0.0}
\definecolor{GOLDENROD}{rgb}{0.75,0.55,0.0}
\definecolor{VIOLET}{rgb}{.7,0.0,0.05}
\definecolor{MIDBLUE}{rgb}{0.08,0.08,1.28}

for the color

Answer 1

In addition to David's suggestion, for the line between the two tabulars, you can use the \vline command. To make the tables the same height (so that the bottom \hline line up) you can simply add two empty lines by using \\ twice.

\begin{figure} [h!tb]
\footnotesize
\centering
\begin{tabular}[t] {l }
\hline
\textcolor{sql}{double} N;\\
\textcolor{sql}{double}[] L;\\
\textcolor{sql}{double}[,] Q;\\
\textcolor{sql}{int} d;\\
\textcolor{sql}{double}[,]rho;\\
\textcolor{sql}{public} NLQ(\textcolor{sql}{int} dimension) \{ \\
~~d    = dimension;\\
~~N    = 0.0;\\
~~L    = new \textcolor{sql}{double}[d];\\
~~Q   = new \textcolor{sql}{double}[d, d];\\
\} \\
\hline
\end{tabular}
\vline
\hspace{1pt}
\begin{tabular}[t] {l }
\hline
\textbf{in}:   $record$, $d$  \\
1 :$n$ += 1\\
2: \textcolor{sql}{For} i=0 to d\\
3: ~~~~$L_i$ += $record_i$\\
4: ~~~~\textcolor{sql}{For} j=0 to i\\
5: ~~~~~~~~$Q_{i,j}$=$Q_{j,i}$= $record_i$*$record_j$ \\
6:~~~~~\textcolor{sql}{End}\\
7:\textcolor{sql}{End}\\
\textbf{out:}  $n$, $L$, $Q$ \\
\\
\\
\hline
\end{tabular}
\caption{NLQ Definition  and Reader Function}
\label{fig:implementNLQ}
\end{figure}    

Answer 2

I'd use nested tables that will allow automatic placement of the rules.

\documentclass{article}
\usepackage{amsmath,array}
\usepackage{xcolor}
\definecolor{sql}{rgb}{0,0,.55}

\newcommand{\+}[1][1]{\unskip\hspace{#1em}\ignorespaces}
\newcommand{\var}[1]{\textit{#1}}
\newcommand{\key}[1]{\text{#1}}
\newcommand{\peq}{\mathrel{{+}{=}}}

\begin{document}
\begin{figure}[htb]
\footnotesize
\centering
\begin{tabular}{@{}l|l@{}}
\hline
\begin{tabular}[t]{l}
\textcolor{sql}{double} $N$;\\
\textcolor{sql}{double}[\,] $L$;\\
\textcolor{sql}{double}[\,,\,] $Q$;\\
\textcolor{sql}{int} $d$;\\
\textcolor{sql}{double}[\,,\,] \var{rho};\\
\textcolor{sql}{public} NLQ(\textcolor{sql}{int} dimension) \{ \\
\+ \begin{tabular}{@{} >{$}r<{$} @{}>{${}}l<{$} @{}}
   d &= \key{dimension};\\
   N &= 0.0;\\
   L &= \key{new \textcolor{sql}{double}}[d];\\
   Q &= \key{new \textcolor{sql}{double}}[d, d];
   \end{tabular}\\
\}
\end{tabular}
&
\begin{tabular}[t]{l}
\textbf{in}:   \var{record}, $d$  \\
1: $n \peq 1$\\
2: \textcolor{sql}{For} $i=0$ to $d$\\
3: \+ $L_i \peq \var{record}_i$\\
4: \+ \textcolor{sql}{For} $j=0$ to $i$\\
5: \+[2] $Q_{i,j}=Q_{j,i}=\var{record}_i * \var{record}_j$ \\
6: \+ \textcolor{sql}{End}\\
7: \textcolor{sql}{End}\\
\textbf{out:}  $n$, $L$, $Q$
\end{tabular}
\\
\hline
\end{tabular}
\caption{NLQ Definition  and Reader Function}
\label{fig:implementNLQ}
\end{figure} 
\end{document}

Note how math is properly segregated to give optimal spacing (and also uniform appearance to the symbols).

The setting of your sql color is dubious, as the values in an rgb specification are normalized to 1 as a maximum, so you're actually declaring pure blue, so I've changed it.

Answer 3

Tables are vertically centred by default, change

\begin{tabular} {l }

to

\begin{tabular}[t] {l }

and they will align on their top line (although a tabular may not be the most convenient structure for laying out code fragments).