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In this article, we determine the maximum Wiener indices of unicyclic graphs with given number of vertices and matching number. We also characterize the extremal graphs. This solves an open problem of Du and Zhou.

Combinatorics · Mathematics 2018-07-17 Stijn Cambie

Over all graphs (or unicyclic graphs) of a given order, we characterise those graphs that minimise or maximise the number of connected induced subgraphs. For each of these classes, we find that the graphs that minimise the number of…

Combinatorics · Mathematics 2019-09-18 Audace A. V. Dossou-Olory

Let $G$ be a connected graph of order $n$.The Wiener index $W(G)$ of $G$ is the sum of the distances between all unordered pairs of vertices of $G$. In this paper we show that the well-known upper bound $\big( \frac{n}{\delta+1}+2\big) {n…

Combinatorics · Mathematics 2023-06-22 Peter Dankelmann , Alex Alochukwu

The Wiener index of a connected graph is the sum of the distances between all pairs of vertices in the graph. It was conjectured that the Wiener index of an $n$-vertex maximal planar graph is at most $\lfloor\frac{1}{18}(n^3+3n^2)\rfloor$.…

Combinatorics · Mathematics 2019-12-09 Debarun Ghosh , Ervin Győri , Addisu Paulos , Nika Salia , Oscar Zamora

The \emph{Wiener index} is a widely studied topological index of graphs. One of the main problems in the area is to determine which graphs of given properties attain the extremal values of Wiener index. In this paper we resolve an open…

Combinatorics · Mathematics 2020-12-22 Jan Bok , Nikola Jedličková , Jana Maxová

The relation between the Wiener index $W(G)$ and the eccentricity $\varepsilon(G)$ of a graph $G$ is studied. Lower and upper bounds on $W(G)$ in terms of $\varepsilon(G)$ are proved and extremal graphs characterized. A Nordhaus-Gaddum type…

Combinatorics · Mathematics 2021-03-04 Hamid Darabi , Yaser Alizadeh , Sandi Klavžar , Kinkar Chandra Das

The Wiener index of a connected graph is the sum of the distances between all unordered pairs of vertices. A connected graph is Eulerian if its vertex degrees are all even. In [Gutman, Cruz, Rada, Wiener index of Eulerian Graphs, Discrete…

Combinatorics · Mathematics 2021-01-22 Peter Dankelmann

Wiener index, defined as the sum of distances between all unordered pairs of vertices, is one of the most popular molecular descriptors. It is well known that among 2-vertex connected graphs on $n\ge 3$ vertices, the cycle $C_n$ attains the…

Discrete Mathematics · Computer Science 2019-05-14 Stéphane Bessy , François Dross , Martin Knor , Riste Škrekovski

The Wiener index of a strong digraph $D$ is defined as the sum of the distances between all ordered pairs of vertices. This definition has been extended to digraphs that are not necessarily strong by defining the distance from a vertex $a$…

Combinatorics · Mathematics 2022-09-20 Peter Dankelmann

The aim of this paper is to obtain new inequalities for a large family of generalizations of the Wiener Index and to characterize the set of extremal graphs with respect to them. Our main results provide upper and lower bounds for these…

Combinatorics · Mathematics 2022-01-17 Álvaro Martínez-Pérez , osé M. Rodríguez

In the original article ``Wiener index of Eulerian graphs'' [Discrete Applied Mathematics Volume 162, 10 January 2014, Pages 247-250], the authors state that the Wiener index (total distance) of an Eulerian graph is maximized by the cycle.…

Combinatorics · Mathematics 2023-09-12 Stijn Cambie

The Wiener index of a (hyper)graph is calculated by summing up the distances between all pairs of vertices. We determine the maximum possible Wiener index of a connected $n$-vertex $k$-uniform hypergraph and characterize for every~$n$ all…

Combinatorics · Mathematics 2023-02-20 Stijn Cambie , Ervin Győri , Nika Salia , Casey Tompkins , James Tuite

Recently, D. Vuki$\check{c}$evi$\acute{c}$ and J. Sedlar in \cite{Vuki} introduced an order "$\preceq$" on $\mathcal{T}_n$, the set of trees on $n$ vertices, such that the topological index $F$ of a graph is a function defined on the order…

Combinatorics · Mathematics 2020-10-09 Rui Song , Qiongxiang Huang , Peng Wang

The Wiener index of a connected graph is the summation of all distances between unordered pairs of vertices of the graph. In this paper, we give an upper bound on the Wiener index of a $k$-connected graph $G$ of order $n$ for integers…

Combinatorics · Mathematics 2018-11-08 Zhongyuan Che , Karen L. Collins

The vertex $k$-partiteness $v_k(G)$ of graph $G$ is defined as the fewest number of vertices whose deletion from $G$ yields a $k$-partite graph. In this paper, we introduce two concepts: monotonic decreasing topological index and monotonic…

Combinatorics · Mathematics 2017-08-04 Fang Gao , Duo Duo Zhao , Xiao-Xin Li , Jia-Bao Liu

In this paper we obtain bounds on a very general class of distance-based topological indices of graphs, which includes the Wiener index, defined as the sum of the distances between all pairs of vertices of the graph, and most…

Combinatorics · Mathematics 2024-11-21 Peter Dankelmann

Hansen et. al. used the computer programm AutoGraphiX to study the differences between the Szeged index $Sz(G)$ and the Wiener index $W(G)$, and between the revised Szeged index $Sz^*(G)$ and the Wiener index for a connected graph $G$. They…

Combinatorics · Mathematics 2012-12-10 Lily Chen , Xueliang Li , Mengmeng Liu

Let $I(G)$ be a topological index of a graph. If $I(G+e)<I(G)$ (or $I(G+e)>I(G)$, respectively) for each edge $e\not\in G$, then $I(G)$ is monotonically decreasing (or increasing, respectively) with the addition of edges. In this article,…

Combinatorics · Mathematics 2017-04-19 Hanlin Chen , Renfang Wu , Hanyuan Deng

The Wiener index of a connected graph is the sum of topological distances between all pairs of vertices. Since Wang gave a mistake result on the maximum Wiener index for given tree degree sequence, in this paper, we investigate the maximum…

Combinatorics · Mathematics 2009-07-23 Xiao-Dong Zhang , Yong Liu , Min-Xian Han

We prove a conjecture of Nadjafi-Arani, Khodashenas and Ashrafi on the difference between the Szeged and Wiener index of a graph. Namely, if $G$ is a 2-connected non-complete graph on $n$ vertices, then $Sz(G)-W(G)\ge 2n-6$. Furthermore,…

Combinatorics · Mathematics 2018-06-29 Marthe Bonamy , Martin Knor , Borut Lužar , Alexandre Pinlou , Riste Škrekovski
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