P515: Enumerate all the acyclic orientations of a graph

P515: Enumerate all the acyclic orientations of a graph
Input:
A graph $G = (V, E)$.
Output:
All acyclic orientations of $G$.
Complexity:
$O(|E|)$ delay with $O(|E|)$ space.
Comment:
Reference:
[Conte2018] (Bibtex)