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Related papers: On Hamiltonicity of {claw, net}-free graphs

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In 1962, Erd\H{o}s proved that if a graph $G$ with $n$ vertices satisfies $$ e(G)>\max\left\{\binom{n-k}{2}+k^2,\binom{\lceil(n+1)/2\rceil}{2}+\left\lfloor \frac{n-1}{2}\right\rfloor^2\right\}, $$ where the minimum degree $\delta(G)\geq k$…

Combinatorics · Mathematics 2018-07-17 Binlong Li , Bo Ning , Xing Peng

Supergrid graphs contain grid graphs and triangular grid graphs as their subgraphs. The Hamiltonian cycle and path problems for general supergrid graphs were known to be NP-complete. A graph is called Hamiltonian if it contains a…

Discrete Mathematics · Computer Science 2019-05-07 Fatemeh Keshavarz-Kohjerdi , Ruo-Wei Hung

Let $G$ be a graph on $n\geq 3$ vertices, claw the bipartite graph $K_{1,3}$, and $Z_i$ the graph obtained from a triangle by attaching a path of length $i$ to its one vertex. $G$ is called 1-heavy if at least one end vertex of each induced…

Combinatorics · Mathematics 2013-01-07 Bo Ning , Bing Chen , Shenggui Zhang

A Hamiltonian path (a Hamiltonian cycle) in a graph is a path (a cycle, respectively) that traverses all of its vertices. The problems of deciding their existence in an input graph are well-known to be NP-complete, in fact, they belong to…

Discrete Mathematics · Computer Science 2025-04-02 Nikola Jedličková , Jan Kratochvíl

A graph $G$ is $l$-path Hamiltonian if every path of length not exceeding $l$ is contained in a Hamiltonian cycle. It is well known that a 2-connected, $k$-regular graph $G$ on at most $3k-1$ vertices is edge-Hamiltonian if for every edge…

Combinatorics · Mathematics 2022-03-10 Xia Li , Weihua Yang

Let $\mathcal{G}(k)$ denote the set of connected $k$-regular graphs $G$, $k\geq2$, where the number of vertices at distance 2 from any vertex in $G$ does not exceed $k$. Asratian (2006) showed (using other terminology) that a graph…

Combinatorics · Mathematics 2021-07-16 Armen S. Asratian , Jonas B. Granholm

In 1981, Duffus, Gould, and Jacobson showed that every connected graph either has a Hamiltonian path, or contains a claw ($K_{1,3}$) or a net (a fixed six-vertex graph) as an induced subgraph. This implies that subject to being connected,…

Combinatorics · Mathematics 2022-08-09 Joseph Cheriyan , Sepehr Hajebi , Zishen Qu , Sophie Spirkl

A graph $G$ is said to be $k$-$\gamma$-vertex critical if the domination numbers $\gamma(G)$ of $G$ is $k$ and $\gamma(G - v) < k$ for any vertex $v$ of $G$. Similarly, A graph $G$ is said to be $k$-$\gamma_{c}$-vertex critical if the…

Combinatorics · Mathematics 2019-11-12 Pawaton Kaemawichanurat

A Hamiltonian path (cycle) in a graph is a path (cycle, respectively) which passes through all of its vertices. The problems of deciding the existence of a Hamiltonian cycle (path) in an input graph are well known to be NP-complete, and…

Combinatorics · Mathematics 2024-03-07 Nikola Jedličková , Jan Kratochvíl

We say that a graph $G$ on $n$ vertices is $\{H,F\}$-$o$-heavy if every induced subgraph of $G$ isomorphic to $H$ or $F$ contains two nonadjacent vertices with degree sum at least $n$. Generalizing earlier sufficient forbidden subgraph…

Combinatorics · Mathematics 2024-09-23 Wangyi Shang , Hajo Broersma , Shenggui Zhang , Binlong Li

We say a graph $G$ has a Hamiltonian path if it has a path containing all vertices of $G$. For a graph $G$, let $\sigma_2(G)$ denote the minimum degree sum of two nonadjacent vertices of $G$; restrictions on $\sigma_2(G)$ are known as…

Combinatorics · Mathematics 2020-01-07 Ilkyoo Choi , Jinha Kim

Given a graph $G$ and a graph property $P$ we say that $G$ is minimal with respect to $P$ if no proper induced subgraph of $G$ has the property $P$. An HC-obstruction is a minimal 2-connected non-Hamiltonian graph. Given a graph $H$, a…

Combinatorics · Mathematics 2023-01-04 Aristotelis Chaniotis , Zishen Qu , Sophie Spirkl

Kronk introduced the $l$-path hamiltonianicity of graphs in 1969. A graph is $l$-path Hamiltonian if every path of length not exceeding $l$ is contained in a Hamiltonian cycle. We have shown that if $P=uvz$ is a 2-path of a 2-connected,…

Combinatorics · Mathematics 2023-11-10 Xia Li , Weihua Yang , Bo Zhang , Shuang Zhao

The path eccentricity of a connected graph $G$ is the minimum integer $k$ such that $G$ has a path such that every vertex is at distance at most $k$ from the path. A result of Duffus, Jacobson, and Gould from 1981 states that every…

Combinatorics · Mathematics 2025-08-21 Sylwia Cichacz , Claire Hilaire , Tomáš Masařík , Jana Masaříková , Martin Milanič

A graph $G$ on $n$ vertices is Hamiltonian if it contains a spanning cycle, and pancyclic if it contains cycles of all lengths from 3 to $n$. In 1984, Fan presented a degree condition involving every pair of vertices at distance two for a…

Combinatorics · Mathematics 2013-12-23 Bo Ning

A supergrid graph is a finite vertex-induced subgraph of the infinite graph whose vertex set consists of all points of the plane with integer coordinates and in which two vertices are adjacent if the difference of their x or y coordinates…

Computational Complexity · Computer Science 2019-08-21 Ruo-Wei Hung , Fatemeh Keshavarz-Kohjerdi

For a fixed set ${\cal H}$ of graphs, a graph $G$ is ${\cal H}$-subgraph-free if $G$ does not contain any $H \in {\cal H}$ as a (not necessarily induced) subgraph. A recently proposed framework gives a complete classification on ${\cal…

Discrete Mathematics · Computer Science 2024-05-07 Vadim Lozin , Barnaby Martin , Sukanya Pandey , Daniel Paulusma , Mark Siggers , Siani Smith , Erik Jan van Leeuwen

A Hamilton cycle is a cycle containing every vertex of a graph. A graph is called Hamiltonian if it contains a Hamilton cycle. The Hamilton cycle problem is to find the sufficient and necessary condition that a graph is Hamiltonian. In this…

Discrete Mathematics · Computer Science 2015-08-04 Heping Jiang

For a connected graph, the Hamiltonian cycle (path) is a simple cycle (path) that spans all the vertices in the graph. It is known from \cite{muller,garey} that HAMILTONIAN CYCLE (PATH) are NP-complete in general graphs and chordal…

Discrete Mathematics · Computer Science 2018-09-18 P. Kowsika , V. Divya , N. Sadagopan

In this paper, we continue the study of the Hamiltonian and longest $(s, t)$-paths of supergrid graphs. The Hamiltonian $(s, t)$-path of a graph is a Hamiltonian path between any two given vertices $s$ and $t$ in the graph, and the longest…

Discrete Mathematics · Computer Science 2019-11-21 Ruo-Wei Hung , Fatemeh Keshavarz-Kohjerdi
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