English
Related papers

Related papers: Packing Cycles Faster Than Erd\H{o}s-P\'osa

200 papers

We prove that there exists a function $f:\mathbb{N}\rightarrow \mathbb{R}$ such that every directed graph $G$ contains either $k$ directed odd cycles where every vertex of $G$ is contained in at most two of them, or a set of at most $f(k)$…

Combinatorics · Mathematics 2024-12-30 Ken-ichi Kawarabayashi , Stephan Kreutzer , O-joung Kwon , Qiqin Xie

A set of cycles is called independent if no two of them have a common vertex. Let $S_{n, 2k-1}$ be the complete split graph, which is the join of a clique of size $2k-1$ with an independent set of size $n-2k+1$. In 1962, Erd\H{o}s and…

Combinatorics · Mathematics 2022-08-08 Zhai Mingqing , Liu Ruifang

Given an undirected graph $G = (V,E)$ with a set of terminals $T\subseteq V$ partitioned into a family $\mathcal{S}$ of disjoint blocks, find the maximum number of vertex-disjoint paths whose endpoints belong to two distinct blocks while no…

Data Structures and Algorithms · Computer Science 2024-11-28 Satoru Iwata , Hirota Kinoshita

$H$-Packing is the problem of finding a maximum number of vertex-disjoint copies of $H$ in a given graph $G$. $H$-Partition is the special case of finding a set of vertex-disjoint copies that cover each vertex of $G$ exactly once. Our goal…

Data Structures and Algorithms · Computer Science 2025-09-09 Barış Can Esmer , Dániel Marx

In 2013, Duch{\^e}ne, Kheddouci, Nowakowski and Tahraoui [4, 9] introduced a labeled version of the graph packing problem. It led to the introduction of a new parameter for graphs, the k-labeled packing number $\lambda$ k. This parameter…

Combinatorics · Mathematics 2018-05-17 Alice Joffard , Hamamache Kheddouci

We present an algorithm for the extensively studied Long Path and Long Cycle problems on unit disk graphs that runs in time $2^{O(\sqrt{k})}(n+m)$. Under the Exponential Time Hypothesis, Long Path and Long Cycle on unit disk graphs cannot…

Data Structures and Algorithms · Computer Science 2020-03-03 Fedor V. Fomin , Daniel Lokshtanov , Fahad Panolan , Saket Saurabh , Meirav Zehavi

We show the following for every sufficiently connected graph $G$, any vertex subset $S$ of $G$, and given integer $k$: there are $k$ disjoint odd cycles in $G$ each containing a vertex of $S$ or there is set $X$ of at most $2k-2$ vertices…

Combinatorics · Mathematics 2016-02-17 Felix Joos

The problem of finding multiple simple shortest paths in a weighted directed graph $G=(V,E)$ has many applications, and is considerably more difficult than the corresponding problem when cycles are allowed in the paths. Even for a single…

Data Structures and Algorithms · Computer Science 2016-02-24 Udit Agarwal , Vijaya Ramachandran

We design the first subexponential-time (parameterized) algorithms for several cut and cycle-hitting problems on $H$-minor free graphs. In particular, we obtain the following results (where $k$ is the solution-size parameter). 1.…

Data Structures and Algorithms · Computer Science 2022-07-05 Sayan Bandyapadhyay , William Lochet , Daniel Lokshtanov , Saket Saurabh , Jie Xue

We study the design of robust subexponential algorithms for classical connectivity problems on intersection graphs of similarly sized fat objects in $\mathbb{R}^d$. In this setting, each vertex corresponds to a geometric object, and two…

Data Structures and Algorithms · Computer Science 2025-12-04 Malory Marin , Jean-Florent Raymond , Rémi Watrigant

For a simple graph $G$, let $n$ and $m$ denote the number of vertices and edges in $G$, respectively. The Erd\H{o}s-Gallai theorem for paths states that in a simple $P_k$-free graph, $m \leq \frac{n(k-1)}{2}$, where $P_k$ denotes a path…

Combinatorics · Mathematics 2025-05-08 Rajat Adak , L. Sunil Chandran

In this paper, we study the complexity of two types of digraph packing problems: perfect out-forests problem and Steiner cycle packing problem. For the perfect out-forest problem, we prove that it is NP-hard to decide whether a given strong…

Combinatorics · Mathematics 2022-11-28 Yuefang Sun

We initiate the algorithmic study of retracting a graph into a cycle in the graph, which seeks a mapping of the graph vertices to the cycle vertices, so as to minimize the maximum stretch of any edge, subject to the constraint that the…

Data Structures and Algorithms · Computer Science 2019-04-29 Samuel Haney , Mehraneh Liaee , Bruce M. Maggs , Debmalya Panigrahi , Rajmohan Rajaraman , Ravi Sundaram

In 1975, Erd\H{o}s asked for the maximum number of edges that an $n$-vertex graph can have if it does not contain two edge-disjoint cycles on the same vertex set. It is known that Tur\'an-type results can be used to prove an upper bound of…

Combinatorics · Mathematics 2024-04-11 Debsoumya Chakraborti , Oliver Janzer , Abhishek Methuku , Richard Montgomery

Research of cycles through specific vertices is a central topic in graph theory. In this context, we focus on a well-studied computational problem, \textsc{$T$-Cycle}: given an undirected $n$-vertex graph $G$ and a set of $k$ vertices…

Data Structures and Algorithms · Computer Science 2025-04-29 Harmender Gahlawat , Abhishek Rathod , Meirav Zehavi

We prove that for every graph, any vertex subset $S$, and given integers $k,\ell$: there are $k$ disjoint cycles of length at least $\ell$ that each contain at least one vertex from $S$, or a vertex set of size $O(\ell \cdot k \log k)$ that…

Combinatorics · Mathematics 2015-04-24 Henning Bruhn , Felix Joos , Oliver Schaudt

We present two on-line algorithms for maintaining a topological order of a directed $n$-vertex acyclic graph as arcs are added, and detecting a cycle when one is created. Our first algorithm handles $m$ arc additions in $O(m^{3/2})$ time.…

Data Structures and Algorithms · Computer Science 2011-05-13 Bernhard Haeupler , Telikepalli Kavitha , Rogers Mathew , Siddhartha Sen , Robert Endre Tarjan

Erd\"os conjectured that if $G$ is a triangle free graph of chromatic number at least $k\geq 3$, then it contains an odd cycle of length at least $k^{2-o(1)}$ \cite{sudakovverstraete, verstraete}. Nothing better than a linear bound…

Discrete Mathematics · Computer Science 2008-09-11 Ajit A. Diwan , Sreyash Kenkre , Sundar Vishwanathan

One of the most fundamental problems in Computer Science is the Knapsack problem. Given a set of n items with different weights and values, it asks to pick the most valuable subset whose total weight is below a capacity threshold T. Despite…

Data Structures and Algorithms · Computer Science 2018-07-16 Kyriakos Axiotis , Christos Tzamos

A subset $C$ of edges in a $k$-uniform hypergraph $H$ is a \emph{loose Hamilton cycle} if $C$ covers all the vertices of $H$ and there exists a cyclic ordering of these vertices such that the edges in $C$ are segments of that order and such…

Combinatorics · Mathematics 2016-08-04 Asaf Ferber , Kyle Luh , Daniel Montealegre , Oanh Nguyen