Abstract
Vertex induced subgraphs of directed de Bruijn graphs with labels of fixed length k and over α letter alphabet are (α,k)-labelled. DNA graphs are (4,k)-labelled graphs. Pendavingh et al. proved that it is NP-hard to determine the smallest value α k (D) for which a directed graph D can be (α k (D),k)-labelled for any fixed \(k \geqslant 3\). In this paper, we obtain the following formulas: \(\alpha_k(C_n)=\lceil\sqrt[k-1]{n}\rceil\) and\(\alpha_k(P_n)=\lceil\sqrt[k-1]{n+1}\rceil\) for cycle C n and path P n . Accordingly, we show that both cycles and paths are DNA graphs. Next we prove that rooted trees and self-adjoint digraphs admit a (Δ,k)-labelling for some positive integer k and they are DNA graphs if and only if Δ ≤ 4, where Δ is the maximum number in all out-degrees and in-degrees of such digraphs.
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References
Bains W., and Smith G.C. (1988). A novel method for nucleic acid sequence determination. J. Theoret. Biol. 135:303–307
Bang-Jensen J. and Gutin G. (2001). Digraphs: Theory, Algorithms and Applications. Springer-Verlag, London
Błażewicz J., Formanowicz P., Kasprzak M., and Kobler D. (2002). On the recognition of de Bruijn graphs and their induced subgraphs. Discrete Math. 245:81–92
Błażewicz J., Hertz A., Kobler D., and de Werra D. (1999). On some properties of DNA graphs. Discrete Appl. Math. 98:1–19
de Bruijn N.G. (1946). A combinatorial problem, Nederl. Akad. Wetensch. 49:758–764 (Indagationes Math. 8 (1946) 461–467)
Hao J. (2005). The adjoints of DNA graphs. J. Math. Chem. 37:333–346
Imori M., Matsumoto M., and Yamada H. (1988). The line digraph of a regular and pancircular digraph is also regular and pancircular. Graphs Combin. 4:235–239
Pendavingh R., Schuurman P., and Woeginger G.J. (2003). Recognizing DNA graphs is difficult. Discrete Appl. Math. 127:85–94
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Li, X., Zhang, H. Characterizations for Some Types of DNA Graphs. J Math Chem 42, 65–79 (2007). https://doi.org/10.1007/s10910-006-9099-4
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DOI: https://doi.org/10.1007/s10910-006-9099-4