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Related papers: Better coloring of 3-colorable graphs

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We study the problem of online graph coloring for $k$-colorable graphs. The best previously known deterministic algorithm uses $\widetilde{O}(n^{1-\frac{1}{k!}})$ colors for general $k$ and $\widetilde{O}(n^{5/6})$ colors for $k = 4$, both…

Data Structures and Algorithms · Computer Science 2026-04-06 Ken-ichi Kawarabayashi , Hirotaka Yoneda , Masataka Yoneda

Vizing's theorem states that any $n$-vertex $m$-edge graph of maximum degree $\Delta$ can be {\em edge colored} using at most $\Delta + 1$ different colors [Diskret.~Analiz, '64]. Vizing's original proof is algorithmic and shows that such…

Data Structures and Algorithms · Computer Science 2024-05-27 Sayan Bhattacharya , Din Carmon , Martín Costa , Shay Solomon , Tianyi Zhang

Since the seminal result of Karger, Motwani, and Sudan, algorithms for approximate 3-coloring have primarily centered around SDP-based rounding. However, it is likely that important combinatorial or algebraic insights are needed in order to…

Discrete Mathematics · Computer Science 2023-11-28 Joshua Brakensiek , Sami Davies

We give a $(1.796+\epsilon)$-approximation for the minimum sum coloring problem on chordal graphs, improving over the previous 3.591-approximation by Gandhi et al. [2005]. To do so, we also design the first polynomial-time approximation…

Data Structures and Algorithms · Computer Science 2024-06-28 Ian DeHaan , Zachary Friggstad

Let $G$ be an $n$-vertex graph with the maximum degree $\Delta$ and the minimum degree $\delta$. We give algorithms with complexity $O(1.3158^{n-0.7~\Delta(G)})$ and $O(1.32^{n-0.73~\Delta(G)})$ that determines if $G$ is 3-colorable, when…

Combinatorics · Mathematics 2020-09-01 Nicholas Crawford , Sogol Jahanbekam , Katerina Potika

This paper is concerned with efficiently coloring sparse graphs in the distributed setting with as few colors as possible. According to the celebrated Four Color Theorem, planar graphs can be colored with at most 4 colors, and the proof…

Combinatorics · Mathematics 2019-10-28 Pierre Aboulker , Marthe Bonamy , Nicolas Bousquet , Louis Esperet

An NP-complete coloring or homomorphism problem may become polynomial time solvable when restricted to graphs with degrees bounded by a small number, but remain NP-complete if the bound is higher. For instance, 3-colorability of graphs with…

Combinatorics · Mathematics 2012-11-29 Aurosish Mishra , Pavol Hell

This paper studies the fundamental problem of graph coloring in fully dynamic graphs. Since the problem of computing an optimal coloring, or even approximating it to within $n^{1-\epsilon}$ for any $\epsilon > 0$, is NP-hard in static…

Data Structures and Algorithms · Computer Science 2020-06-23 Shay Solomon , Nicole Wein

We provide novel deterministic distributed vertex coloring algorithms. As our main result, we give a deterministic distributed algorithm to compute a $(\Delta+1)$-coloring of an $n$-node graph with maximum degree $\Delta$ in…

Data Structures and Algorithms · Computer Science 2019-07-10 Fabian Kuhn

In the $\ell$-Coloring Problem, we are given a graph on $n$ nodes, and tasked with determining if its vertices can be properly colored using $\ell$ colors. In this paper we study below-guarantee graph coloring, which tests whether an…

Data Structures and Algorithms · Computer Science 2025-09-17 Shyan Akmal , Tomohiro Koana

Given a graph $G$ and color set $\{1, \ldots, k\}$, a $\textit{proper coloring}$ is an assignment of a color to each vertex of $G$ such that no two vertices connected by an edge are given the same color. The problem of drawing a proper…

Computational Complexity · Computer Science 2020-06-11 Mark Huber

The $\Delta$-vertex coloring problem has become one of the prototypical problems for understanding the complexity of local distributed graph problems on constant-degree graphs. The major open problem is whether the problem can be solved…

Distributed, Parallel, and Cluster Computing · Computer Science 2025-04-08 Manuel Jakob , Yannic Maus

We present a new algorithm for finding large independent sets in $3$-colorable graphs with small $1$-sided threshold rank. Specifically, given an $n$-vertex $3$-colorable graph whose uniform random walk matrix has at most $r$ eigenvalues…

Data Structures and Algorithms · Computer Science 2025-08-06 Jun-Ting Hsieh

Coloring a graph $G$ consists in finding an assignment of colors $c: V(G)\to\{1,\ldots,p\}$ such that any pair of adjacent vertices receives different colors. The minimum integer $p$ such that a coloring exists is called the chromatic…

Discrete Mathematics · Computer Science 2019-12-25 Théo Pierron

The notion of $S$-labeling of graphs, where $S$ is a subset of a symmetric group, was introduced in 2019 by Jin, Wong, and Zhu. This notion provides the framework for a common generalization of various well studied notions of graph…

Combinatorics · Mathematics 2024-10-22 Samantha L. Dahlberg , Hemanshu Kaul , Jeffrey A. Mudrock

A graph $G$ has maximal local edge-connectivity $k$ if the maximum number of edge-disjoint paths between every pair of distinct vertices $x$ and $y$ is at most $k$. We prove Brooks-type theorems for $k$-connected graphs with maximal local…

Combinatorics · Mathematics 2022-03-07 Pierre Aboulker , Nick Brettell , Frédéric Havet , Dániel Marx , Nicolas Trotignon

Lokshtanov, Marx, and Saurabh SODA 2011 proved that there is no $(k-\epsilon)^{\operatorname{pw}(G)}\operatorname{poly}(n)$ time algorithm for deciding if an $n$-vertex graph $G$ with pathwidth $\operatorname{pw}(G)$ admits a proper vertex…

Data Structures and Algorithms · Computer Science 2015-07-10 Andreas Björklund

This paper investigates an extremely classic NP-complete problem: How to determine if a graph G, where each vertex has a degree of at most 4, can be 3-colorable(The research in this paper focuses on graphs G that satisfy the condition where…

Computational Complexity · Computer Science 2024-05-21 Zikang Deng

We consider the graph $k$-colouring problem encoded as a set of polynomial equations in the standard way over $0/1$-valued variables. We prove that there are bounded-degree graphs that do not have legal $k$-colourings but for which the…

Computational Complexity · Computer Science 2023-06-02 Massimo Lauria , Jakob Nordström

We show that given an $n$-vertex graph $G$ of diameter 3 we can decide if $G$ is $3$-colourable in time $2^{O(n^{2/3-\varepsilon})}$ for any $\varepsilon < 1/33$. This improves on the previous best algorithm of $2^{O((n\log n)^{2/3})}$ from…

Combinatorics · Mathematics 2026-05-26 Carla Groenland , Hidde Koerts , Sophie Spirkl