P430: Enumeration of all cycles in a directed graph

P430: Enumeration of all cycles in a directed graph
Input:
A graph $G = (V, E)$.
Output:
All cycles in $G$.
Complexity:
$O(|E| + c(|V| \times |E|))$ total, where $c$ is the number of circuits in $G$.
Comment:
Reference:
[Ehrenfeucht1973] (Bibtex)