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相关论文: On Hamiltonicity of {claw, net}-free graphs

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In this paper, we investigate Hamiltonian path problem in the context of split graphs, and produce a dichotomy result on the complexity of the problem. Our main result is a deep investigation of the structure of $K_{1,4}$-free split graphs…

离散数学 · 计算机科学 2017-11-28 P. Renjith , N. Sadagopan

Let $G$ be a graph on $n\geq 3$ vertices. A graph $G$ is almost distance-hereditary if each connected induced subgraph $H$ of $G$ has the property $d_{H}(x,y)\leq d_{G}(x,y)+1$ for any pair of vertices $x,y\in V(H)$. A graph $G$ is called…

组合数学 · 数学 2016-06-13 Bing Chen , Bo Ning

A claw-free graph is a graph that does not contain $K_{1,3}$ as an induced subgraph, and a 2-factor is a 2-regular spanning subgraph of a graph. In 1997, Ryj\'{a}\v{c}ek introduced the closure concept of claw-free graphs, and Hamilton…

组合数学 · 数学 2025-04-14 Masaki Kashima

We study the Hamiltonian path problem in C-shaped grid graphs, and present the necessary and sufficient conditions for the existence of a Hamiltonian path between two given vertices in these graphs. We also give a linear-time algorithm for…

计算复杂性 · 计算机科学 2016-02-25 Fatemeh Keshavarz-Kohjerdi , Alireza Bagheri

In light of Lov\'{a}sz's longstanding question on the existence of Hamilton paths in vertex-transitive graphs, this paper considers a natural variant: what if vertex-transitivity is relaxed, yet a high degree of symmetry--specifically…

组合数学 · 数学 2026-02-17 Shaofei Du , Kai Yuan

For a connected graph, a path containing all vertices is known as \emph{Hamiltonian path}. For general graphs, there is no known necessary and sufficient condition for the existence of Hamiltonian paths and the complexity of finding a…

离散数学 · 计算机科学 2016-07-21 P. Renjith , N. Sadagopan

The connected graph of degree sequence 3,3,3,1,1,1 is called a net, and the vertices of degree 1 in a net is called its endvertices. Broersma conjectured in 1993 that a 2-connected graph G with no induced K_{1,3} is hamiltonian if every…

组合数学 · 数学 2018-03-28 Shuya Chiba , Jun Fujisawa

A bipartite graph is chordal bipartite if every cycle of length at least six has a chord in it. M$\ddot{\rm u}$ller \cite {muller1996Hamiltonian} has shown that the Hamiltonian cycle problem is NP-complete on chordal bipartite graphs by…

离散数学 · 计算机科学 2021-07-13 S. Aadhavan , R. Mahendra Kumar , P. Renjith , N. Sadagopan

A graph is Hamiltonian if it contains a cycle which visits every vertex of the graph exactly once. In this paper, we consider the problem of Hamiltonicity of a graph $G_n$, which will be called the prime difference graph of order $n$, with…

组合数学 · 数学 2020-04-10 Hong-Bin Chen , Hung-Lin Fu , Jun-Yi Guo

A graph is called \emph{claw-free} if it contains no induced subgraph isomorphic to $K_{1,3}$. Matthews and Sumner proved that a 2-connected claw-free graph $G$ is hamiltonian if every vertex of it has degree at least $(|V(G)|-2)/3$. At the…

组合数学 · 数学 2016-06-27 Roman Čada , Binlong Li , Bo Ning , Shenggui Zhang

We continue studying Thomassen's conjecture (every 4-connected line graph has a Hamilton cycle) in the direction of a recently shown equivalence with Jackson's conjecture (every 2-connected claw-free graph has a Tutte cycle), and we extend…

组合数学 · 数学 2025-03-11 Adam Kabela , Zdeněk Ryjáček , Petr Vrána

A graph G on n vertices is Hamiltonian if it contains a cycle of length n and pancyclic if it contains cycles of length $\ell$ for all $3 \le \ell \le n$. Write $\alpha(G)$ for the independence number of $G$, i.e. the size of the largest…

组合数学 · 数学 2009-03-27 Peter Keevash , Benny Sudakov

A disconnected cut of a connected graph is a vertex cut that itself also induces a disconnected subgraph. The decision problem whether a graph has a disconnected cut is called Disconnected Cut. This problem is closely related to several…

数据结构与算法 · 计算机科学 2018-03-13 Barnaby Martin , Daniel Paulusma , Erik Jan van Leeuwen

A graph is \emph{hamiltonian-connected} if every pair of vertices can be connected by a hamiltonian path, and it is \emph{hamiltonian} if it contains a hamiltonian cycle. We construct families of non-hamiltonian graphs for which the ratio…

Let $t>0$ be a real number and $G$ be a graph. We say $G$ is $t$-tough if for every cutset $S$ of $G$, the ratio of $|S|$ to the number of components of $G-S$ is at least $t$. Determining toughness is an NP-hard problem for arbitrary…

组合数学 · 数学 2019-01-10 Songling Shan

A graph $G$ is $k$-edge-Hamiltonian if any collection of vertex-disjoint paths with at most $k$ edges altogether belong to a Hamiltonian cycle in $G$. A graph $G$ is $k$-Hamiltonian if for all $S\subseteq V(G)$ with $|S|\le k$, the subgraph…

组合数学 · 数学 2024-04-09 Yongtao Li , Yuejian Peng

A cycle $C$ of length $k$ in graph $G$ is extendable if there is another cycle $C'$ in $G$ with $V(C) \subset V(C')$ and length $k+1$. A graph is cycle extendable if every non-Hamiltonian cycle is extendable. In 1990 Hendry conjectured that…

组合数学 · 数学 2016-03-01 Deborah Arangno , David E. Brown

Given a 3-uniform hypergraph H, its 2-intersection graph G has for vertex set the hyperedges of H and ee' is an edge of G whenever e and e' have exactly two common vertices in H. Di Marco et al. prove that deciding wether a graph G is the…

组合数学 · 数学 2023-05-24 Niccolò Di Marco , Andrea Frosini , Christophe Picouleau

For a graph $G$, the $t$-th power $G^t$ is the graph on $V(G)$ such that two vertices are adjacent if and only if they have distance at most $t$ in $G$; and the $t$-th bi-power $G_B^t$ is the graph on $V(G)$ such that two vertices are…

组合数学 · 数学 2019-02-19 Binlong Li

We introduce a closure technique for Hamilton-connectedness of $\{K_{1,3},\Gamma_3\}$-free graphs, where $\Gamma_3$ is the graph obtained by joining two vertex-disjoint triangles with a path of length $3$. The closure turns a claw-free…

组合数学 · 数学 2024-07-26 Adam Kabela , Zdeněk Ryjáček , Mária Skyvová , Petr Vrána