A black hole in a directed graph is a vertex that has no outgoing edges and has incoming edges from all other vertices. This code proves that it is inned possible to determine whether a graph has a black hole in O(|V|) time, not as commonly thought O(|V| + |E|) time or O(|V|**2) time. It was written to validate my CSI3105 Assignment 2.
SPDX-License-Identifier: GPL-3.0-or-later