Abstract
Let G be a connected graph. The Szeged index of G is defined as \(Sz(G)=\sum \nolimits _{e=uv\in E(G)}n_{u}(e|G)n_{v}(e|G)\), where \(n_{u}(e|G)\) (resp., \(n_{v}(e|G)\)) is the number of vertices whose distance to vertex u (resp., v) is smaller than the distance to vertex v (resp., u), and \(n_{0}(e|G)\) is the number of vertices equidistant from both ends of e. Let \(\mathcal {M}(2\beta )\) be the set of unicyclic graphs with order \(2\beta \) and a perfect matching. In this paper, we determine the minimum value of Szeged index and characterize the extremal graph with the minimum Szeged index among all unicyclic graphs with perfect matchings.
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References
Dobrynin AA (1997) Graphs having maximal value of the Szeged index. Croat Chem Acta 70:819–825
Dobrynin AA, Gutman I (1997) Szeged index of some polycyclic bipartite graphs with circuits of different size. MATCH Commun Math Comput Chem 35:117–128
Dobrynin AA, Entringer R, Gutman I (2001) Wiener index of trees: theory and applications. Acta Appl Math 66:211–249
Gutman I (1994) A formula for the Wiener number of trees and its extension to graphs containing cycles. Graph Theory Notes NY 27:9–15
Gutman I, Dobrynin AA (1998) The Szeged index-A success story. Graph Theory Notes NY 34:37–44
Gutman I, Klavzar S (1995) An algorithm for the calculation of the Szeged index of benzenoid hydrocarbons. J Chem Inf Comput Sci 35:1011–1014
Gutman I, Polansky OE (1986) Mathematical concepts in organic chemistry. Springer, Berlin
Gutman I, Khadikar PV, Rajput PV, Karmarkar S (1995) The Szeged index of polyacenes. J Serb Chem Soc 60:759–764
Gutman I, Popovic L, Khadikar PV, Karmarkar S, Joshi S, Mandloi M (1997) Relations between Wiener and Szeged indices of monocyclic. Molecules 35:91–103
Khadikar PV, Deshpande NV, Kale PP, Dobrynin AA, Gutman I, Domotor G (1995) The Szeged index and an analogy with the Wiener index. J Chem Inf Comput Sci 35:547–550
Khadikar P, Kale P, Deshpande N, Karmarkar S, Agrawal V (2000) Szeged indices of hexagonal chains. MATCH Commun Math Comput Chem 43:7–15
Khadikar PV, Karmarkar S, Agrawal VK, Singh J, Shrivastava A, Lukovits I, Diudea MV (2005) Szeged index-applications for drug modeling. Lett Drug Des Discov 2:606–624
Klavzar S, Rajapakse A, Gutman I (1996) The Szeged and the Wiener index of graphs. Appl Math Lett 9:45–49
Nikolic S, Trinajstic N, Mihalic Z (1995) The Wiener index: development and applications. Croat Chem Acta 68:105–129
Randic M (2002) On generalization of Wiener index for cyclic structures. Acta Chim Slov 49:483–496
Rouvray DH (2002) The rich legacy of half of a century of the Wiener index. In: Rouvray DH, King RB (eds) Topology in chemistry-discrete mathematics of chemistry. Horwood, Chichester
Simic S, Gutman I, Baltic V (2000) Some graphs with extremal Szeged index. Math Slovaca 50:1–15
Tutte WT (1974) The factorization of linear graphs. J Lond Math Soc 2:107–111
Wang S (2017) On extremal cacti with respect to the Szeged index. Appl Math Comput 309:85–92
Zhang H, Li S, Zhao L (2016) On the further relation between the (revised) Szeged index and the Wiener index of graphs. Discrete Appl Math 206:152–164
Zhou B, Cai X, Du Z (2010) On Szeged indices of unicyclic graphs. MATCH Commun Math Comput Chem 63:113–132
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This paper supported by program for excellent talents in Hunan Normal University (ET13101).
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Liu, H., Deng, H. & Tang, Z. Minimum Szeged index among unicyclic graphs with perfect matchings. J Comb Optim 38, 443–455 (2019). https://doi.org/10.1007/s10878-019-00390-5
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DOI: https://doi.org/10.1007/s10878-019-00390-5