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Related papers: Variations of the cop and robber game on graphs

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We prove that every connected $P_5$-free graph has cop number at most two, solving a conjecture of Sivaraman. In order to do so, we first prove that every connected $P_5$-free graph $G$ with independence number at least three contains a…

Combinatorics · Mathematics 2025-10-29 Maria Chudnovsky , Sergey Norin , Paul Seymour , Jérémie Turcotte

Pursuit-evasion games, such as the game of Revolutionaries and Spies, are a simplified model for network security. In the game we consider in this paper, a team of $r$ revolutionaries tries to hold an unguarded meeting consisting of $m$…

Combinatorics · Mathematics 2014-06-12 Dieter Mitsche , Pawel Pralat

We prove that the cop number of any $2K_2$-free graph is at most 2, proving a conjecture of Sivaraman and Testa. We also show that the upper bound of $3$ on the cop number of $2K_1+K_2$-free (co-diamond--free) graphs is best possible.

Combinatorics · Mathematics 2025-10-29 Jérémie Turcotte

We prove that for each $D\ge 2$ there exists $c>0$ such that whenever $b\le c\big(\tfrac{n}{\log n}\big)^{1/D}$, in the $(1:b)$ Maker-Breaker game played on $E(K_n)$, Maker has a strategy to guarantee claiming a graph $G$ containing copies…

Combinatorics · Mathematics 2017-11-16 Peter Allen , Julia Böttcher , Yoshiharu Kohayakawa , Humberto Naves , Yury Person

A solution to a problem of Erd\H{o}s, Rubin and Taylor is obtained by showing that if a graph $G$ is $(a:b)$-choosable, and $c/d > a/b$, then $G$ is not necessarily $(c:d)$-choosable. The simplest case of another problem, stated by the same…

Discrete Mathematics · Computer Science 2008-02-18 Shai Gutner

In chomp on graphs, two players alternatingly pick an edge or a vertex from a graph. The player that cannot move any more loses. The questions one wants to answer for a given graph are: Which player has a winning strategy? Can a explicit…

Combinatorics · Mathematics 2018-04-19 Ignacio García-Marco , Kolja Knauer , Luis Pedro Montejano

The semi-random graph process is a single-player game that begins with an empty graph on $n$ vertices. In each round, a vertex $u$ is presented to the player independently and uniformly at random. The player then adaptively selects a vertex…

Combinatorics · Mathematics 2024-03-05 Natalie C. Behague , Trent G. Marbach , Pawel Pralat , Andrzej Rucinski

We consider the localization game played on graphs in which a cop tries to determine the exact location of an invisible robber by exploiting distance probes. The corresponding graph parameter $\zeta(G)$ for a given graph $G$ is called the…

Combinatorics · Mathematics 2020-09-07 Andrzej Dudek , Sean English , Alan Frieze , Calum MacRury , Pawel Pralat

We investigate a variation of the graph coloring game, as studied in [2]. In the original coloring game, two players, Alice and Bob, alternate coloring vertices on a graph with legal colors from a fixed color set, where a color {\alpha} is…

Combinatorics · Mathematics 2014-12-10 Michel Alexis , Davis Shurbert , Charles Dunn , Jennifer Nordstrom

In the $\left(1:b\right)$ component game played on a graph $G$, two players, Maker and Breaker, alternately claim~$1$ and~$b$ previously unclaimed edges of $G$, respectively. Maker's aim is to maximise the size of a largest connected…

Combinatorics · Mathematics 2020-12-18 Rani Hod , Michael Krivelevich , Tobias Müller , Alon Naor , Nicholas Wormald

The cops-and-robber (CR) game has been used in mobile robotics as a discretized model (played on a graph G) of pursuit/evasion problems. The "classic" CR version is a perfect information game: the cops' (pursuer's) location is always known…

Discrete Mathematics · Computer Science 2014-02-26 Athanasios Kehagias , Dieter Mitsche , Pawel Pralat

This paper describes a 720-vertex connected planar graph G such that cop1(G), denoting the minimum number of cops needed to catch the robber in the 1-cop-move game on G, is at least 4 and at most 7. Furthermore, G has a connected subgraph H…

Discrete Mathematics · Computer Science 2019-12-17 Wei Quan Lim

The game of cops and robbers is a well-known game played on graphs. In this paper we consider the straight-ahead orientations of 4-regular quadrangulations of the torus and the Klein bottle and we prove that their cop number is bounded by a…

The network coloring game has been proposed in the literature of social sciences as a model for conflict-resolution circumstances. The players of the game are the vertices of a graph with $n$ vertices and maximum degree $\Delta$. The game…

Discrete Mathematics · Computer Science 2022-04-01 Nikolaos Fryganiotis , Symeon Papavassiliou , Christos Pelekis

We explore a variant of the game of Cops and Robber introduced by Bonato et al.~where the robber is invisible unless outside the common neighbourhood of the cops. The hyperopic cop number is analogous to the cop number and we investigate…

Combinatorics · Mathematics 2021-07-16 Nancy E. Clarke , Stephen Finbow , Margaret-Ellen Messinger , Amanda Porter

We study a game on a graph $G$ played by $r$ {\it revolutionaries} and $s$ {\it spies}. Initially, revolutionaries and then spies occupy vertices. In each subsequent round, each revolutionary may move to a neighboring vertex or not move,…

Discrete Mathematics · Computer Science 2015-08-06 Jane V. Butterfield , Daniel W. Cranston , Gregory J. Puleo , Douglas B. West , Reza Zamani

We consider a variation of Cops and Robber, introduced in [D. Cox and A. Sanaei, The damage number of a graph, [Aust. J. of Comb. 75(1) (2019) 1-16] where vertices visited by a robber are considered damaged and a single cop aims to minimize…

Combinatorics · Mathematics 2024-12-19 Melissa A. Huggan , Margaret-Ellen Messinger , Amanda Porter

The Maker-Breaker connectivity game and Hamilton cycle game belong to the best studied games in positional games theory, including results on biased games, games on random graphs and fast winning strategies. Recently, the Connector-Breaker…

Combinatorics · Mathematics 2023-06-02 Dennis Clemens , Pranshu Gupta , Yannick Mogge

We consider two conjectures made in regard to the graph grabbing game, played on a vertex weighted graph. Seacrest and Seacrest conjectured in 2012 that the first player can win the graph grabbing game on any even-order bipartite graph. Eoh…

Combinatorics · Mathematics 2023-11-07 Lawrence Hollom

This paper introduced a pursuit and evasion game to be played on a connected graph. One player moves invisibly around the graph, and the other player must guess his position. At each time step the second player guesses a vertex, winning if…

Combinatorics · Mathematics 2017-01-24 John Haslegrave