PACE 2022 Heuristic (PACE 2022 Directed Feedback Vertex Set, HeuristicTrack)

This is the set of graphs used in the PACE 2022 challenge for computing the Directed Feedback Vertex Set, from the Heuristic track. It consists of 200 labelled directed graphs. The graphs are mostly not symmetric (an edge form u->v does not imply an edge from v->u), although some are symmetric. The graph labels are integers ranging from 1 to N.

There is the related PACE 2022 Exact dataset, which was for exact computation; those graphs are generally smaller and sparser, as only exact solutions were accepted.

The data format begins with one line N E 0, where N is the number of vertices, E is the number of edges, and 0 is the literal integer zero. The N subsequent lines are each a space-separated list of integers, such as 2 5 11 19. If that appeared on line number 1 (the first after N E 0), it would indicate that there are edges from vertex 1 to each of the vertices 2, 5, 11, and 19. Some lines are blank, and these indicates vertices with outdegree zero. An example graph would be

4 4 0
2 3
3

1

The dataset can be downloaded here. The 100 instances that were available for public testing are precisely the odd-numbered ones in that link; the public instances can be downloaded on their own here.