Article
Keywords:
radio antipodal colouring; radio number; distance labeling
Summary:
The radio antipodal number of a graph $G$ is the smallest integer $c$ such that there exists an assignment $f\: V(G)\rightarrow \lbrace 1,2,\ldots ,c\rbrace $ satisfying $|f(u)-f(v)|\ge D-d(u,v)$ for every two distinct vertices $u$ and $v$ of $G$, where $D$ is the diameter of $G$. In this note we determine the exact value of the antipodal number of the path, thus answering the conjecture given in [G. Chartrand, D. Erwin and P. Zhang, Math. Bohem. 127 (2002), 57–69]. We also show the connections between this colouring and radio labelings.
References:
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Radio labelings of graphs. Bull. Inst. Combin. Appl. 33 (2001), 77–85.
MR 1913399
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Radio antipodal colorings of cycles. Congr. Numerantium 144 (2000), 129–141.
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[3] G. Chartrand, D. Erwin, P. Zhang:
Radio antipodal colorings of graphs. Math. Bohem. 127 (2002), 57–69.
MR 1895247
[6] D. Liu, X. Zhu: Multi-level distance labelings for paths and cycles. (to appear).