{ "id": "1806.04628", "version": "v1", "published": "2018-06-12T16:21:08.000Z", "updated": "2018-06-12T16:21:08.000Z", "title": "The Game of Zombies and Survivors on the Cartesian Products of Trees", "authors": [ "Shannon L. Fitzpatrick" ], "comment": "9 pages", "categories": [ "math.CO", "cs.DM" ], "abstract": "We consider the game of Zombies and Survivors as introduced by Fitzpatrick, Howell, Messinger and Pike (2016) This is a variation of the game Cops and Robber where the zombies (in the cops' role) are of limited intelligence and will always choose to move closer to a survivor (who takes on the robber's role). The zombie number of a graph is defined to be the minimum number of zombies required to guarantee the capture of a survivor on the graph. In this paper, we show that the zombie number of the Cartesian product of $n$ non-trivial trees is exactly $\\lceil 2n/3 \\rceil$. This settles a conjecture by Fitzpatrick et. al. (2016) that this is the zombie number for the $n$-dimensional hypercube. In proving this result, we also discuss other variations of Cops and Robber involving active and flexible players.", "revisions": [ { "version": "v1", "updated": "2018-06-12T16:21:08.000Z" } ], "analyses": { "keywords": [ "cartesian product", "zombie number", "move closer", "robbers role", "fitzpatrick" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable" } } }