Journal of East China Normal University(Natural Sc ›› 2019, Vol. 2019 ›› Issue (1): 39-47,57.doi: 10.3969/j.issn.1000-5641.2019.01.005

• Mathematics • Previous Articles     Next Articles

L(2, 1)-labelling of Halin graphs with a maximum degree of seven

CHEN Xiao-feng, WANG Yi-qiao   

  1. School of Management, Beijing University of Chinese Medicine, Beijing 100029, China
  • Received:2018-05-07 Online:2019-01-25 Published:2019-01-24

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Abstract: A Halin graph is a plane graph G=T ∪ C, where T is a tree with no vertex of degree 2 and at least one vertex of degree 3 or more, and C is a cycle connecting the leaves of T in the cyclic order determined by the drawing of T. After structural analysis of Halin graphs, we show that the L(2,1)-labelling number of every Halin graph G with a maximum degree 7 is at most 10.

Key words: Halin graph, L(2,1)-labelling, maximum degree

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