{ "id": "2307.09389", "version": "v1", "published": "2023-07-18T16:13:39.000Z", "updated": "2023-07-18T16:13:39.000Z", "title": "Algorithms and hardness for Metric Dimension on digraphs", "authors": [ "Antoine Dailly", "Florent Foucaud", "Anni Hakanen" ], "comment": "20 pages. Full version of the paper presented at WG2023", "categories": [ "math.CO", "cs.DM" ], "abstract": "In the Metric Dimension problem, one asks for a minimum-size set R of vertices such that for any pair of vertices of the graph, there is a vertex from R whose two distances to the vertices of the pair are distinct. This problem has mainly been studied on undirected graphs and has gained a lot of attention in the recent years. We focus on directed graphs, and show how to solve the problem in linear-time on digraphs whose underlying undirected graph (ignoring multiple edges) is a tree. This (nontrivially) extends a previous algorithm for oriented trees. We then extend the method to unicyclic digraphs (understood as the digraphs whose underlying undirected multigraph has a unique cycle). We also give a fixed-parameter-tractable algorithm for digraphs when parameterized by the directed modular-width, extending a known result for undirected graphs. Finally, we show that Metric Dimension is NP-hard even on planar triangle-free acyclic digraphs of maximum degree 6.", "revisions": [ { "version": "v1", "updated": "2023-07-18T16:13:39.000Z" } ], "analyses": { "keywords": [ "undirected graph", "planar triangle-free acyclic digraphs", "metric dimension problem", "unique cycle", "unicyclic digraphs" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }