Put these lines to preamble (the preamble is everything from the start of the LaTeX source file until the \begin{document} command):
\renewcommand\lstlistingname{Algorithm}
\renewcommand\lstlistlistingname{Algorithms}
The first changes the caption name for listings. The second — the header name for the list of listings which is printed by the \lstlistoflistings command. You would also probably want to modify the text in autorefs:
\def\lstlistingautorefname{Alg.}
Then when you’re referring to a particular listing, e. g. For details see \autoref{sec2:bubblesort}. it is written as “For details see Alg. 2.1.”