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Related papers: 2-Coloring Cycles in One Round

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Coloring is a notoriously hard problem, and even more so in the online setting, where each arriving vertex has to be colored immediately and irrevocably. Already on trees, which are trivially two-colorable, it is impossible to achieve…

Data Structures and Algorithms · Computer Science 2024-05-29 Fabian Frei , Matthias Gehnen , Dennis Komm , Rastislav Královič , Richard Královič , Peter Rossmanith , Moritz Stocker

Let $S$ be a set of four points chosen independently, uniformly at random from a square. Join every pair of points of $S$ with a straight line segment. Color these edges red if they have positive slope and blue, otherwise. We show that the…

We prove several new tight distributed lower bounds for classic symmetry breaking graph problems. As a basic tool, we first provide a new insightful proof that any deterministic distributed algorithm that computes a $\Delta$-coloring on…

Distributed, Parallel, and Cluster Computing · Computer Science 2022-06-03 Alkida Balliu , Sebastian Brandt , Fabian Kuhn , Dennis Olivetti

Given an $r$-edge-colouring of the edges of a graph $G$, we say that it can be partitioned into $p$ monochromatic cycles when there exists a set of $p$ vertex-disjoint monochromatic cycles covering all the vertices of $G$. In the literature…

Combinatorics · Mathematics 2025-06-05 Fabrício Siqueira Benevides , Arthur Lima Quintino , Alexandre Talon

We prove that for all graphs with at most $(3.75-o(1))n$ edges there exists a 2-coloring of the edges such that every monochromatic path has order less than $n$. This was previously known to be true for graphs with at most $2.5n-7.5$ edges.…

Combinatorics · Mathematics 2021-11-05 Deepak Bal , Louis DeBiasio

We give a new randomized distributed algorithm for $(\Delta+1)$-coloring in the LOCAL model, running in $O(\sqrt{\log \Delta})+ 2^{O(\sqrt{\log \log n})}$ rounds in a graph of maximum degree~$\Delta$. This implies that the…

Data Structures and Algorithms · Computer Science 2023-10-13 David G. Harris , Johannes Schneider , Hsin-Hao Su

We give a new, simple distributed algorithm for graph colouring in paths and cycles. Our algorithm is fast and self-contained, it does not need any globally consistent orientation, and it reduces the number of colours from $10^{100}$ to $3$…

Distributed, Parallel, and Cluster Computing · Computer Science 2017-09-05 Jukka Kohonen , Janne H. Korhonen , Christopher Purcell , Jukka Suomela , Przemysław Uznański

Gy\'arf\'as and Lehel and independently Faudree and Schelp proved that in any 2-coloring of the edges of $K_{n,n}$ there exists a monochromatic path on at least $2\lceil n/2\rceil$ vertices, and this is tight. We prove a stability version…

Combinatorics · Mathematics 2018-06-14 Louis DeBiasio , Robert A. Krueger

In a simple, undirected graph G, an edge 2-coloring is a coloring of the edges such that no vertex is incident to edges with more than 2 distinct colors. The problem maximum edge 2-coloring (ME2C) is to find an edge 2-coloring in a graph G…

Discrete Mathematics · Computer Science 2025-05-07 Tobias Mömke , Alexandru Popa , Aida Roshany-Tabrizi , Michael Ruderer , Roland Vincze

The paper deals with extremal problems concerning colorings of hypergraphs. By using a random recoloring algorithm we show that any $n$-uniform simple (i.e. every two distinct edges share at most one vertex) hypergraph $H$ with maximum edge…

Combinatorics · Mathematics 2014-09-25 Jakub Kozik , Dmitry Shabanov

We prove that a random graph $G(n,p)$, with $p$ above the Hamiltonicity threshold, is typically such that for any $r$-colouring of its edges there exists a Hamilton cycle with at least $(2/(r+ 1)-o(1))n$ edges of the same colour. This…

Combinatorics · Mathematics 2021-04-22 Lior Gishboliner , Michael Krivelevich , Peleg Michaeli

We present a deterministic distributed algorithm in the LOCAL model that finds a proper $(\Delta + 1)$-edge-coloring of an $n$-vertex graph of maximum degree $\Delta$ in $\mathrm{poly}(\Delta, \log n)$ rounds. This is the first nontrivial…

Combinatorics · Mathematics 2021-03-08 Anton Bernshteyn

For a hypergraph $H$, let $q(H)$ denote the expected number of monochromatic edges when the color of each vertex in $H$ is sampled uniformly at random from the set of size 2. Let $s_{\min}(H)$ denote the minimum size of an edge in $H$.…

Combinatorics · Mathematics 2021-12-17 Lech Duraj , Grzegorz Gutowski , Jakub Kozik

We give efficient randomized and deterministic distributed algorithms for computing a distance-$2$ vertex coloring of a graph $G$ in the CONGEST model. In particular, if $\Delta$ is the maximum degree of $G$, we show that there is a…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-05-15 Magnus M. Halldorsson , Fabian Kuhn , Yannic Maus

It is easy to see that every $k$-edge-colouring of the complete graph on $2^k+1$ vertices contains a monochromatic odd cycle. In 1973, Erd\H{o}s and Graham asked to estimate the smallest $L(k)$ such that every $k$-edge-colouring of…

Combinatorics · Mathematics 2026-04-01 Oliver Janzer , Fredy Yip

As the main contribution of this work we present deterministic edge coloring algorithms in the CONGEST model. In particular, we present an algorithm that edge colors any $n$-node graph with maximum degree $\Delta$ with with…

Data Structures and Algorithms · Computer Science 2026-03-04 Joakim Blikstad , Yannic Maus , Tijn de Vos

We give an improved randomized CONGEST algorithm for distance-$2$ coloring that uses $\Delta^2+1$ colors and runs in $O(\log n)$ rounds, improving the recent $O(\log \Delta \cdot \log n)$-round algorithm in [Halld\'orsson, Kuhn, Maus; PODC…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-08-11 Magnus M. Halldorsson , Fabian Kuhn , Yannic Maus , Alexandre Nolin

In this paper we study fractional coloring from the angle of distributed computing. Fractional coloring is the linear relaxation of the classical notion of coloring, and has many applications, in particular in scheduling. It was proved by…

Distributed, Parallel, and Cluster Computing · Computer Science 2021-03-15 Nicolas Bousquet , Louis Esperet , François Pirot

In this short note we show that every connected $2$-edge coloured cubic graph admits an $10$-colouring. This lowers the best known upper bound for the chromatic number of connected $2$-edge coloured cubic graphs.

Discrete Mathematics · Computer Science 2019-10-28 Christopher Duffy

In the minimum sum edge coloring problem, we aim to assign natural numbers to edges of a graph, so that adjacent edges receive different numbers, and the sum of the numbers assigned to the edges is minimum. The {\em chromatic edge strength}…

Discrete Mathematics · Computer Science 2008-01-22 Jean Cardinal , Vlady Ravelomanana , Mario Valencia-Pabon