# Can adjacency lists be used in directed graphs?

It says that that graph can be constructed with the list $\{b, c\}, \{a, c\}, \{a, b\}$.

However, what if I wanted to construct a directional list? Does $\{b, c\}$ point to $b$ or $c$?

How can you use a list to represent a directional graph?

Your graph is actually undirected. The notation is a list of edges in the graph. Since edges are undirected, each edge is a set of two vertices. Your lists contains three edges, since a triangle has three edges. It actually contains all possible edges involving the vertices $a,b,c$.
Does $\{b,c\}$ point to $b$ or $c$?
Neither. The adjacency list representation of a graph, you are given, for each vertex $x$, a list of the vertices adjacent to $x$. Thus, the lists $\{b,c\}$, $\{a,c\}$, $\{a,b\}$, tell you that $a$ is adjacent to $b$ and $c$, $b$ is adjacent to $a$ and $c$ and $c$ $is$ adjacent to $a$ and $b$.
You shouldn't confuse this with the notation $\{x,y\}$ for the undirected edge connecting $x$ and $y$.