Abstract
The covering radius of binary 2-surjective codes of maximum length is studied in the paper. It is shown that any binary 2-surjective code of M codewords and of length \(n = {M-1 \choose \left\lfloor(M-2)/2\right\rfloor}\) has covering radius \(\frac{n}{2} - 1\) if M − 1 is a power of 2, otherwise \(\left\lfloor\frac{n}{2}\right\rfloor\) . Two different combinatorial proofs of this assertion were found by the author. The first proof, which is written in the paper, is based on an existence theorem for k-uniform hypergraphs where the degrees of its vertices are limited by a given upper bound. The second proof, which is omitted for the sake of conciseness, is based on Baranyai’s theorem on l-factorization of a complete k-uniform hypergraph.
Similar content being viewed by others
References
Baranyai Zs.: On the factorization of the complete uniform hypergraph, Infinite and finite sets (Colloq., Keszthely, 1973; dedicated to P. Erdős on his 60th birthday), vol. I, Colloq. Math. Soc. János Bolyai, vol. 10, pp. 91–108. North-Holland, Amsterdam (1975).
Billington D. (1986). Lattices and degree sequences of uniform hypergraphs. Ars Combin. 21A: 9–19
Bollobás B. (1973). Sperner systems consisting of pairs of complementary subsets. J. Combin. Theory Ser. A. 15, 363–366
Brace A., Daykin D.E.: Sperner type theorems for finite sets, Combinatorics (Proc. Conf. Combinatorial Math., Math. Inst., Oxford) In: Welsch J.A., Woodall D.R. (eds.), Inst. Math. Appl., Southend-on-Sea, pp. 18–37 (1972).
Erdős P., Ko C., Rado R. (1961). Intersection theorems for systems of finite sets. Quart. J. Math. Oxford 12, 313–318
Katona G.O.H. (1973). Two applications (for search theory and truth functions) of Sperner type theorems. Period. Math. Hungar. 3, 19–26
Kéri G., Tuza Zs.: Balanced degree sequences of uniform hypergraphs. Note, manuscript.
Kleitman D.J., Spencer J. (1973). Families of k-independent sets. Discrete Math. 6, 255–262
Rényi A. (1971). Foundations of Probability. Wiley, New York
Sperner E. (1928). Ein Satz über Untermengen einer endlichen Menge. Math. Z. 27, 544–548
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by R.C. Mullin.
Rights and permissions
About this article
Cite this article
Kéri, G. The covering radius of extreme binary 2-surjective codes. Des. Codes Cryptogr. 46, 191–198 (2008). https://doi.org/10.1007/s10623-007-9150-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10623-007-9150-x
Keywords
- Covering radius
- Divisibility of binomial coefficients
- Factorization
- Minimum distance
- Surjective code
- Uniform hypergraph