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Related papers: A faster algorithm for Cops and Robbers

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Cops and robbers is a turn-based pursuit game played on a graph $G$. One robber is pursued by a set of cops. In each round, these agents move between vertices along the edges of the graph. The cop number $c(G)$ denotes the minimum number of…

Combinatorics · Mathematics 2011-09-09 Andrew Beveridge , Andrzej Dudek , Alan Frieze , Tobias Müller

The game of \emph{Cops and Robber} is usually played on a graph, where a group of cops attempt to catch a robber moving along the edges of the graph. The \emph{cop number} of a graph is the minimum number of cops required to win the game.…

Combinatorics · Mathematics 2024-04-29 Joshua Erde , Mihyun Kang , Florian Lehner , Bojan Mohar , Dominik Schmid

We give a $O^*(k^{O(k)})$ time isomorphism testing algorithm for graphs of eigenvalue multiplicity bounded by $k$ which improves on the previous best running time bound of $O^*(2^{O(k^2/\log k)})$.

Computational Complexity · Computer Science 2014-08-18 Vikraman Arvind , Gaurav Rattan

The concept of $k$-defective clique, a relaxation of clique by allowing up-to $k$ missing edges, has been receiving increasing interests recently. Although the problem of finding the maximum $k$-defective clique is NP-hard, several…

Data Structures and Algorithms · Computer Science 2024-03-13 Lijun Chang

We investigate the game of cops and robber, played on a finite graph, between one cop and one robber. If the cop can force a win on a graph, the graph is called cop-win. We describe a procedure we call corner ranking, performed on a graph,…

Combinatorics · Mathematics 2017-03-14 David Offner , Kerry Ojakian

In the cops and robber game, there are multiple cops and a single robber taking turns moving along the edges of a graph. The goal of the cops is to capture the robber (move to the same vertex as the robber) and the goal of the robber is to…

Combinatorics · Mathematics 2024-12-04 Suryaansh Jain , Subrahmanyam Kalyanasundaram , Kartheek Sriram Tammana

We generalise the popular cops and robbers game to multi-layer graphs, where each cop and the robber are restricted to a single layer (or set of edges). We show that initial intuition about the best way to allocate cops to layers is not…

Combinatorics · Mathematics 2026-02-10 Jessica Enright , Kitty Meeks , William Pettersson , John Sylvester

We consider a game in which a cop searches for a moving robber on a graph using distance probes, which is a slight variation on one introduced by Seager. Carragher, Choi, Delcourt, Erickson and West showed that for any n-vertex graph $G$…

Combinatorics · Mathematics 2020-08-12 John Haslegrave , Richard A. B. Johnson , Sebastian Koch

The game of cops and robbers is played on a fixed (finite or infinite) graph $G$. The cop chooses his starting position, then the robber chooses his. After that, they take turns and move to adjacent vertices, or stay at their current…

Combinatorics · Mathematics 2025-07-31 Tomáš Flídr , Maria-Romina Ivan

We consider online algorithms for the $k$-server problem on trees. There is a $k$-competitive algorithm for this problem, and it is the best competitive ratio. M. Chrobak and L. Larmore provided it. At the same time, the existing…

Data Structures and Algorithms · Computer Science 2022-05-02 Kamil Khadiev , Maxim Yagafarov

We investigate extremal graphs related to the game of Cops and Robbers. We focus on graphs where a single cop can catch the robber; such graphs are called cop-win. The capture time of a cop-win graph is the minimum number of moves the cop…

Combinatorics · Mathematics 2019-03-21 David Offner , Kerry Ojakian

Detecting if a graph contains a $k$-Clique is one of the most fundamental problems in computer science. The asymptotically fastest algorithm runs in time $O(n^{\omega k/3})$, where $\omega$ is the exponent of Boolean matrix multiplication.…

Data Structures and Algorithms · Computer Science 2024-08-06 Amir Abboud , Nick Fischer , Yarin Shechter

We consider the (exact, minimum) $k$-cut problem: given a graph and an integer $k$, delete a minimum-weight set of edges so that the remaining graph has at least $k$ connected components. This problem is a natural generalization of the…

Data Structures and Algorithms · Computer Science 2019-10-08 Jason Li

In the $k$-cut problem, we are given an edge-weighted graph and want to find the least-weight set of edges whose deletion breaks the graph into $k$ connected components. Algorithms due to Karger-Stein and Thorup showed how to find such a…

Data Structures and Algorithms · Computer Science 2019-11-22 Anupam Gupta , Euiwoong Lee , Jason Li

We construct a new quantum algorithm for the graph collision problem; that is, the problem of deciding whether the set of marked vertices contains a pair of adjacent vertices in a known graph G. The query complexity of our algorithm is…

Quantum Physics · Physics 2012-04-09 Dmitry Gavinsky , Tsuyoshi Ito

We consider a variation of cop vs.\ robber on graph in which the robber is not restricted by the graph edges; instead, he picks a time-independent probability distribution on $V(G)$ and moves according to this fixed distribution. The cop…

Combinatorics · Mathematics 2013-08-23 Natasha Komarov , Peter Winkler

We consider the cops and robber game variant consisting of one cop and one robber on time-varying graphs (TVG). The considered TVGs are edge periodic graphs, i.e., for each edge, a binary string $s_e$ determines in which time step the edge…

Computational Complexity · Computer Science 2021-07-13 Nils Morawietz , Petra Wolf

We study space and time efficient quantum algorithms for two graph problems -- deciding whether an $n$-vertex graph is a forest, and whether it is bipartite. Via a reduction to the s-t connectivity problem, we describe quantum algorithms…

Quantum Physics · Physics 2016-10-04 Chris Cade , Ashley Montanaro , Aleksandrs Belovs

The computation of the winning set for parity objectives and for Streett objectives in graphs as well as in game graphs are central problems in computer-aided verification, with application to the verification of closed systems with strong…

Data Structures and Algorithms · Computer Science 2019-03-14 Krishnendu Chatterjee , Monika Henzinger , Veronika Loitzenbauer

We consider a variant of the Cops and Robbers game where the robber can move t edges at a time, and show that in this variant, the cop number of a d-regular graph with girth larger than 2t+2 is Omega(d^t). By the known upper bounds on the…

Combinatorics · Mathematics 2011-06-03 Abbas Mehrabian