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Maximum weight independent sets for (\(S_{1,2,4}\), triangle)-free graphs in polynomial time. (English) Zbl 1517.05164

Summary: The Maximum Weight Independent Set (MWIS) problem on finite undirected graphs with vertex weights asks for a set of pairwise nonadjacent vertices of maximum weight sum. MWIS is one of the most investigated and most important algorithmic graph problems; it is well known to be NP-complete, and it remains NP-complete even under various strong restrictions such as for triangle-free graphs. Its complexity for \(P_k\)-free graphs, \(k \geq 7\), is an open problem. In [A. Brandstädt and R. Mosca, Discrete Appl. Math. 236, 57–65 (2018; Zbl 1377.05185)], it is shown that MWIS can be solved in polynomial time for (\( P_7\),triangle)-free graphs. This result is extended by F. Maffray and L. Pastor [Discrete Math. 341, No. 5, 1449–1458 (2018; Zbl 1383.05145)] showing that MWIS can be solved in polynomial time for (\( P_7\),bull)-free graphs. In the same paper, they also showed that MWIS can be solved in polynomial time for (\( S_{1 , 2 , 3}\),bull)-free graphs. In this paper, using a similar approach as in [Brandstädt and Mosca, loc. cit.], we show that MWIS can be solved in polynomial time for (\( S_{1 , 2 , 4}\),triangle)-free graphs which generalizes the result for (\(P_7\),triangle)-free graphs.

MSC:

05C85 Graph algorithms (graph-theoretic aspects)
05C69 Vertex subsets with special properties (dominating sets, independent sets, cliques, etc.)
68W40 Analysis of algorithms

References:

[1] Ahuja, R. K.; Magnanti, T. L.; Orlin, J. B., Network Flows (1993), Prentice Hall · Zbl 1201.90001
[2] Alekseev, V. E., On the local restriction effect on the complexity of finding the graph independence number, (Combinatorial-Algebraic Methods in Applied Mathematics (1983), Gorkiy University Press: Gorkiy University Press Gorkiy), 3-13, (in Russian)
[3] Alekseev, V. E., A polynomial algorithm for finding largest independent sets in fork-free graphs, Discrete Anal. Oper. Res. Ser. 1, 6, 3-19 (1999), (in Russian) (see also [4] for the English version) · Zbl 0931.05078
[4] Alekseev, V. E., A polynomial algorithm for finding largest independent sets in graphs without forks, Discrete Appl. Math., 135, 3-16 (2004) · Zbl 0931.05078
[5] Alekseev, V. E., On easy and hard hereditary classes of graphs with respect to the independent set problem, Discrete Appl. Math., 132, 17-26 (2004) · Zbl 1029.05140
[6] Brandstädt, A.; Le, V. B.; Spinrad, J. P., Graph Classes: A Survey, SIAM Monographs on Discrete Math. Appl., vol. 3 (1999), SIAM: SIAM Philadelphia · Zbl 0919.05001
[7] Brandstädt, A.; Mosca, R., Maximum weight independent sets for \(( P_7\),triangle)-free graphs in polynomial time, Discrete Appl. Math., 236, 57-65 (2018) · Zbl 1377.05185
[8] Brandstädt, A.; Mosca, R., Maximum weight independent set for ℓclaw-free graphs in polynomial time, Discrete Appl. Math., 237, 57-64 (2018) · Zbl 1380.05147
[9] Desler, J. F.; Hakimi, S. L., On finding a maximum stable set of a graph, (Proc. 4th Annual Princeton Conf. on Information Science and Systems. Proc. 4th Annual Princeton Conf. on Information Science and Systems, Princeton, NJ (1970))
[10] Faenza, Y.; Oriolo, G.; Stauffer, G., An algorithmic decomposition of claw-free graphs leading to an \(O( n^3)\)-algorithm for the weighted independent set problem, SODA 2011. SODA 2011, J. ACM, 61, 4, Article 20 pp. (July 2014) · Zbl 1321.05260
[11] Farber, M.; Hujter, M.; Tuza, Zs., An upper bound on the number of cliques in a graph, Networks, 23, 75-83 (1993)
[12] Garey, M. R.; Johnson, D. S., Computers and Intractability: A Guide to the Theory of NP-Completeness (1979), Freeman: Freeman San Francisco, CA · Zbl 0411.68039
[13] Grötschel, M.; Lovász, L.; Schrijver, A., Geometric Algorithms and Combinatorial Optimization (1988), Springer: Springer Berlin · Zbl 0634.05001
[14] Grzesik, A.; Klimosova, T.; Pilipczuk, Marcin; Pilipczuk, Michal, Polynomial-time algorithm for maximum weight independent set on P6-free graphs, (Chan, Timothy M., Proceedings of the 18 Thirtieth Annual ACM-SIAM Symposium on Discrete Algorithms. Proceedings of the 18 Thirtieth Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2019, San Diego, California, USA, January 6-9, 2019 (2019), SIAM), 1257-1271 · Zbl 1431.68047
[15] Hujter, M.; Tuza, Zs., The number of maximal independent sets in triangle-free graphs, SIAM J. Discrete Math., 6, 2, 284-288 (1993) · Zbl 0779.05025
[16] Karp, R. M., Reducibility among combinatorial problems, (Miller, R. E.; Thatcher, J. W., Complexity of Computer Computations (1972), Plenum Press: Plenum Press New York), 85-103 · Zbl 1467.68065
[17] Lokshtanov, D.; Pilipczuk, M.; van Leeuwen, E. J., Independence and efficient domination on \(P_6\)-free graphs, Proc. SODA 2016. Proc. SODA 2016, ACM Trans. Algorithms, 14, 1, Article 3 pp. (2018) · Zbl 1431.68049
[18] Lokshantov, D.; Vatshelle, M.; Villanger, Y., Independent set in \(P_5\)-free graphs in polynomial time, (Chekuri, C., Proceedings of the Twenty-Fifth Annual ACM-SIAM Symposium on Discrete Algorithms. Proceedings of the Twenty-Fifth Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2014, Portland, Oregon, USA, January 5-7, 2014 (2014), SIAM), 570-581 · Zbl 1422.68126
[19] Lozin, V. V., From matchings to independent sets, Discrete Appl. Math., 231, 4-14 (2017) · Zbl 1369.05174
[20] Lozin, V. V.; Milanič, M., A polynomial algorithm to find an independent set of maximum weight in a fork-free graph, J. Discret. Algorithms, 6, 595-604 (2008) · Zbl 1154.90607
[21] Maffray, F.; Pastor, L., The maximum weight stable set problem in \(( P_6\),bull)-free graphs, extended abstract, (Heggernes, P., Graph-Theoretic Concepts in Computer Science - 42nd International Workshop, Revised Selected Papers. Graph-Theoretic Concepts in Computer Science - 42nd International Workshop, Revised Selected Papers, WG 2016, Istanbul, Turkey, June 22-24, 2016. Graph-Theoretic Concepts in Computer Science - 42nd International Workshop, Revised Selected Papers. Graph-Theoretic Concepts in Computer Science - 42nd International Workshop, Revised Selected Papers, WG 2016, Istanbul, Turkey, June 22-24, 2016, LNCS, vol. 9941 (2015)), 85-96, Full version: CoRR · Zbl 1417.05223
[22] Maffray, F.; Pastor, L., Maximum weight stable set in \(( P_7\), bull)-free graphs and \(( S_{1 , 2 , 3}\), bull)-free graphs, Discrete Math., 341, 1449-1458 (2018) · Zbl 1383.05145
[23] Minty, G. J., On maximal independent sets of vertices in claw-free graphs, J. Comb. Theory, Ser. B, 28, 284-304 (1980) · Zbl 0434.05043
[24] Mosca, R., Independent sets in \(( P_4 + P_4\), triangle)-free graphs, CoRR arXiv · Zbl 1479.05282
[25] Nakamura, D.; Tamura, A., A revision of Minty’s algorithm for finding a maximum weight independent set in a claw-free graph, J. Oper. Res. Soc. Jpn., 44, 194-204 (2001) · Zbl 1128.05318
[26] Nobili, P.; Sassano, A., An \(O( n^2 l o g(n))\) algorithm for the weighted stable set problem in claw-free graphs, Math. Program., 186, 409-437 (2021) · Zbl 1458.05203
[27] McConnell, R. M.; Spinrad, J. P., Modular decomposition and transitive orientation, Discrete Math., 201, 189-241 (1999) · Zbl 0933.05146
[28] Möhring, R. H.; Radermacher, F. J., Substitution decomposition for discrete structures and connections with combinatorial optimization, Ann. Discrete Math., 19, 257-356 (1984) · Zbl 0567.90073
[29] Olariu, S., Paw-free graphs, Inf. Process. Lett., 28, 53-54 (1988) · Zbl 0654.05063
[30] Olariu, S., On the closure of triangle-free graphs under substitution, Inf. Process. Lett., 34, 97-101 (1990) · Zbl 0702.68056
[31] Poljak, S., A note on independent sets and colorings of graphs, Commun. Math. Univ. Carolinae, 15, 307-309 (1974) · Zbl 0284.05105
[32] Prömel, H.-J.; Schickinger, T.; Steger, A., A note on triangle-free and bipartite graphs, Discrete Math., 257, 531-540 (2002) · Zbl 1008.05077
[33] Sbihi, N., Algorithme de recherche d’un independent de cardinalité maximum dans un graphe sans étoile, Discrete Math., 29, 53-76 (1980) · Zbl 0444.05049
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