including a C++ code in my latex document

I am trying to include a C++ code in my latex document. However, what I have tried is not working. Everything else works fine, but I am not seeing the C++ showing up as a C++ code. It is just written in the same format as the "Alpha particles .." text

Here is the MWE: The tex is:

\documentclass{article}
\usepackage{listings}
\usepackage{xcolor}
\lstset {
language=C++,
backgroundcolor=\color{black!5}, % set backgroundcolor
basicstyle=\footnotesize,% basic font setting
}

\begin{document}
Alpha particles \cite{wikip} (named \cite{Comp} after and denoted by the first letter     in the
Greek alphabet,$\alpha$) consist of two protons and two neutrons bound
together.
This means that an particle is a helium nucleus.

\begin{lstlisting}
int size =1;
*ptr = Mole:getMole(size + 1);
\end{lstlisting}

\bibliographystyle{plain}
\bibliography{BibName}

\end{document}


Expected result:

• basicstyle=\footnotesize\ttfamily – Steven B. Segletes Dec 17 '14 at 0:44
• I added an image to the question (as it's easier than adding it to a comment) basically your file works without error and produces the result shown. Do you get an error (eg missing package??) – David Carlisle Dec 17 '14 at 0:44
• Yes, I get the error ! LaTeX Error: File listings.sty' not found. Type X to quit or <RETURN> to proceed, or enter new name. (Default extension: sty) Other than using listings, is there another way I can add C++ code to the latex file? – user4352158 Dec 17 '14 at 0:46
• You could have mentioned that in the question:-) listings is part of any tex distribution so if you have texlive or miktex the package manager should be able to install it for you – David Carlisle Dec 17 '14 at 0:53
• If you don't need syntax highlight you could just use \begin{verbatim} ...\end[verbatim} which needs no package, but better to update your installation to include listings – David Carlisle Dec 17 '14 at 0:54

You want to use a different font family for the listing. Since keywords are boldface in the style, the standard Computer Modern Typewriter fonts aren't well suited, because they don't have bold face.

A good monospaced font family that distinguishes well between medium series and boldface is BeraMono.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{listings}
\usepackage{xcolor}
\usepackage[scaled=.85]{beramono}

\lstset{
language=C++,
backgroundcolor=\color{black!5}, % set backgroundcolor
basicstyle=\footnotesize\ttfamily,% basic font setting
columns=fullflexible,
}

\begin{document}

Alpha particles (named after and denoted by the first letter in the Greek alphabet,
$\alpha$) consist of two protons and two neutrons bound together. This means that an
particle is a helium nucleus.

\begin{lstlisting}
int size =1;
*ptr = Mole:getMole(size + 1);
\end{lstlisting}

\end{document}


Note that for an inline formula you use $\alpha$ or $$\alpha$$, rather than $\alpha$ which would center the formula.

I removed the citations that are irrelevant for this topic.

If you are unable to get listings working, there is the verbatimbox package if you don't need keyword highlighting.

Here I show listings and verbatimbox for comparison. By using the verbnobox environment, one can obtain page-breaks in the middle of the listing.

\documentclass{article}
\usepackage{xcolor}
% LISTINGS PREP
\usepackage{listings}
\lstset {
language=C++,
backgroundcolor=\color{black!5}, % set backgroundcolor
basicstyle=\footnotesize,% basic font setting
}
% VERBATIMBOX PREP
\usepackage{verbatimbox}
\def\codesize{\footnotesize}
\newsavebox\thecolorfield
\newcommand\setcolorfield[1][blue!9!gray!8]{%
\savebox{\thecolorfield}{\codesize%
\makebox[0pt][l]{\textcolor{#1}{%
\rule[-\dp\strutbox]{\textwidth}{\dimexpr\ht\strutbox+\dp\strutbox}}}}%
}
\def\colorfield{\usebox{\thecolorfield}}
\setcolorfield
%
\begin{document}
WITH LISTINGS:
\begin{lstlisting}
int size =1;
*ptr = Mole:getMole(size + 1);
\end{lstlisting}

WITH VERBATIMBOX (ttfamily):
\begin{verbnobox}[\colorfield\ttfamily\codesize]
int size =1;
*ptr = Mole:getMole(size + 1);
\end{verbnobox}

\setcolorfield[green!8]
WITH VERBATIMBOX (bold-rmfamily):
\begin{verbnobox}[\colorfield\rmfamily\bfseries\codesize]
int size =1;
*ptr = Mole:getMole(size + 1);
\end{verbnobox}
\end{document}
`