\newsection
\section{Graphs}

\subsection{Repetition}
The graph algorithms of Kruskal, Prim, Boruvka, Dijkstra, Bellman-Ford, Floyd-Warshall and Johnson are still of importance. See A \& D summary for them

\begin{definition}[]{$\alpha$-approximation algorithm}
    This kind of algorithm approximates the result to level $\alpha$, where $\alpha$ is the factor by which the result is off. Ideally, $\alpha = 1$, for a perfect approximation, which in reality is hardly ever, if ever possible.
\end{definition}