The following code is in the preamble of my LaTeX document:
\documentclass{llncs}
\usepackage{amsmath,amssymb}
\usepackage{url}
\usepackage[algoruled,vlined]{algorithm2e}
\usepackage{graphicx,subfigure}
\usepackage{hyperref}
\hypersetup{colorlinks=true,citecolor=blue}
\numberwithin{equation}{section} % numbering according to the section
\bibliographystyle{plain} %Choose a bibliograhpic style
\begin{document}
\title{The Title}
\maketitle
\section{A}
\label{sect:A}
\subsection{a}
\subsection{b}
% ...
\section{B}
\label{sect:B}
\subsection{a}
\subsection{b}
% ...
\section{C}
\label{sect:C}
\subsection{a}
\subsection{b}
% ...
\end{document}
Note that the text is organized into sections and subsection. However, after compiling the code, the Adobe PDF preview does not show the "tree" branching on the left. Instead, it just shows "The Title", and that option has no branching with the "+/-" sings. How could I achieve this?
\section
s and\subsection
s here. Please have a look if it is right.llncs
class can be found at springer.com/computer/lncs?SGWID=0-164-6-793341-0 if someone wants to compile the example.llncs