Note on the Reformulated Zagreb Indices of Two Classes of Graphs
The reformulated Zagreb indices of a graph are obtained from the original Zagreb indices by replacing vertex degrees with edge degrees, where the degree of an edge is taken as the sum of degrees of its two end vertices minus 2. In this paper, we obtain two upper bounds of the first reformulated Zagr...
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Series: | Journal of Chemistry |
Online Access: | http://dx.doi.org/10.1155/2020/4860327 |
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doaj-ba8609e797e74b398c61fb773fa0f93a2020-11-25T02:38:45ZengHindawi LimitedJournal of Chemistry2090-90632090-90712020-01-01202010.1155/2020/48603274860327Note on the Reformulated Zagreb Indices of Two Classes of GraphsTongkun Qu0Mengya He1Shengjin Ji2Xia Li3School of Science, Shandong University of Technology, Zibo, Shandong 255000, ChinaSchool of Science, Shandong University of Technology, Zibo, Shandong 255000, ChinaSchool of Science, Shandong University of Technology, Zibo, Shandong 255000, ChinaSchool of Science, Shandong University of Technology, Zibo, Shandong 255000, ChinaThe reformulated Zagreb indices of a graph are obtained from the original Zagreb indices by replacing vertex degrees with edge degrees, where the degree of an edge is taken as the sum of degrees of its two end vertices minus 2. In this paper, we obtain two upper bounds of the first reformulated Zagreb index among all graphs with p pendant vertices and all graphs having key vertices for which they will become trees after deleting their one key vertex. Moreover, the corresponding extremal graphs which attained these bounds are characterized.http://dx.doi.org/10.1155/2020/4860327 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Tongkun Qu Mengya He Shengjin Ji Xia Li |
spellingShingle |
Tongkun Qu Mengya He Shengjin Ji Xia Li Note on the Reformulated Zagreb Indices of Two Classes of Graphs Journal of Chemistry |
author_facet |
Tongkun Qu Mengya He Shengjin Ji Xia Li |
author_sort |
Tongkun Qu |
title |
Note on the Reformulated Zagreb Indices of Two Classes of Graphs |
title_short |
Note on the Reformulated Zagreb Indices of Two Classes of Graphs |
title_full |
Note on the Reformulated Zagreb Indices of Two Classes of Graphs |
title_fullStr |
Note on the Reformulated Zagreb Indices of Two Classes of Graphs |
title_full_unstemmed |
Note on the Reformulated Zagreb Indices of Two Classes of Graphs |
title_sort |
note on the reformulated zagreb indices of two classes of graphs |
publisher |
Hindawi Limited |
series |
Journal of Chemistry |
issn |
2090-9063 2090-9071 |
publishDate |
2020-01-01 |
description |
The reformulated Zagreb indices of a graph are obtained from the original Zagreb indices by replacing vertex degrees with edge degrees, where the degree of an edge is taken as the sum of degrees of its two end vertices minus 2. In this paper, we obtain two upper bounds of the first reformulated Zagreb index among all graphs with p pendant vertices and all graphs having key vertices for which they will become trees after deleting their one key vertex. Moreover, the corresponding extremal graphs which attained these bounds are characterized. |
url |
http://dx.doi.org/10.1155/2020/4860327 |
work_keys_str_mv |
AT tongkunqu noteonthereformulatedzagrebindicesoftwoclassesofgraphs AT mengyahe noteonthereformulatedzagrebindicesoftwoclassesofgraphs AT shengjinji noteonthereformulatedzagrebindicesoftwoclassesofgraphs AT xiali noteonthereformulatedzagrebindicesoftwoclassesofgraphs |
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1715426987232722944 |