Abstract
In this paper we establish that decidingt-colorability for a simplek-graph whent≧3,k≧3 is NP-complete. Next, we establish that if there is a polynomial time algorithm for finding the chromatic number of a Steiner Triple system then there exists a polynomial time “approximation” algorithm for the chromatic number of simple 3-graphs. Finally, we show that the existence of such an approximation algorithm would imply that P=NP.
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C. J. Colbourn, M. J. Colbourn, K. T. Phelps andV. Rödl, Coloring Steiner quadruple systems,Discrete Applied Math. 4 (1982), 103–111.
A. Cruse, On embedding incomplete symmetric latin squares,J. Combinatorial Theory (A) 16 (1974), 18–27.
P. Erdős andA. Hajnal, On the chromatic number of graphs and set systems,Acta Math. Acad. Sci. Hungar. 17 (1966), 61–99.
P. Erdős andL. Lovász, Problems and results on 3-chromatic hypergraphs and related questions,Infinite and Finite Sets, Proc. Conf. Keszthely (1973),Colloq. Math. Soc. J. Bolyai 10. 609–627.
B. Ganter, Endliche Vervollständigung endlicher Partieller Steinersche Systeme,Arch. Math. 22 (1971), 328–332.
B. Ganter, Finite partial quadruple systems can be finitely embedded,Discrete Math. 10 (1974), 397–400.
M. R. Garey andD. S. Johnson, The complexity of near-optimal graph coloring,J.A.C.M. 23, 43–49.
M. R. Garey andD. S. Johnson,Computers and Intractability—A guide to NP-completeness, W. H. Freeman and Company, 1979.
M. R. Garey, D. S. Johnson andL. Stockmeyer, Some simplified NP-complete graph problems,Theoretical Comp. Sci. 1 (1976), 237–267.
E. L. Lawler,Combinatorial Optimization: Networks and Matroids, Holt, Rinehart and Winston, New York.
C. C. Lindner, A partial Steiner triple system of ordern can be embedded in a Steiner triple system of order 6n + 3,J. Combinatorial Theory (A),18 (1975), 349–351.
C. C. Lindner, A survey of embedding theorems for Steiner systems, in:Topics on Steiner Systems, Ann. Discrete Math. 7 (1980), 175–202.
L. Lovász, Coverings and colorings of hypergraphs,Proc. 45 th Southeastern Conf. Combinatorics, Graph Theory, Computing (1973), 3–12.
K. T. Phelps, V. Rödl anddeBrandes, Coloring Steiner triple Systems,SIAM Alg. and Discrete Methods (to appear).
R. Quackenbush, Near vector spaces over GF(q) and (v, q + 1, 1)—BIBDS,Linear Alg. Appl. 10 (1975), 259–266.
C. A. Treash, The completion of finite incomplete Steiner triple systems with applications to loop theory,J. Combinatorial Theory (A) 10 (1971), 259–265.
C. J. Colbourn, M. J. Colbourn, K. T. Phelps andV. Rödl, Coloring Block Designs is NP-complete,SIAM J. Alg. Disc. Math. 3 (1982), 305–307.
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Dedicated to Paul Erdős on his seventieth birthday
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Phelps, K.T., Rödl, V. On the algorithmic complexity of coloring simple hypergraphs and steiner triple systems. Combinatorica 4, 79–88 (1984). https://doi.org/10.1007/BF02579160
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DOI: https://doi.org/10.1007/BF02579160