Abstract
A new variant of the classic problem of Vertex Cover (VC) is introduced. Either Connected Vertex Cover (CVC) or Eternal Vertex Cover (EVC) is already a variant of VC, and Eternal Connected Vertex Cover (ECVC) is an eternal version of CVC, or a connected version of EVC. A connected vertex cover of a connected graph G is a vertex cover of G inducing a connected subgraph in G. CVC is the problem of computing a minimum connected vertex cover. For EVC a multi-round game on G is considered, and in response to every attack on some edge e of G, a guard positioned on a vertex of G must cross e to repel it. EVC asks the minimum number of guards to be placed on the vertices of a given G, that is sufficient to repel any sequence of edge attacks of an arbitrary length.
ECVC is EVC in which any configuration of guards, that is the set of vertices occupied by them, needs to be kept connected in each round. This paper presents, besides some basic structural properties of ECVC, 1) a polynomial time algorithm for ECVC on chordal graphs, 2) NP-completeness of ECVC on locally connected graphs, 3) a complete characterization of ECVC on cactus graphs, block graphs, or any graphs in which every block is either a simple cycle or a clique, and 4) a 2-approximation algorithm for ECVC on general graphs.
This work is supported in part by JSPS KAKENHI under Grant Number 17K00013.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Anderson, M., Barrientos, C., Brigham, R.C., Carrington, J.R., Vitray, R.P., Yellen, J.: Maximum-demand graphs for eternal security. J. Combin. Math. Combin. Comput. 61, 111–127 (2007)
Arkin, E.M., Halldórsson, M.M., Hassin, R.: Approximating the tree and tour covers of a graph. Inform. Process. Lett. 47(6), 275–282 (1993)
Babu, J., Chandran, L.S., Francis, M., Prabhakaran, V., Rajendraprasad, D., Warrier, J.N.: On graphs with minimal eternal vertex cover number. In: Pal, S.P., Vijayakumar, A. (eds.) CALDAM 2019. LNCS, vol. 11394, pp. 263–273. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-11509-8_22
Blažej, V., Křišt’an, J.M., Valla, T.: On the \(m\)-eternal domination number of cactus graphs. In: Filiot, E., Jungers, R., Potapov, I. (eds.) RP 2019. LNCS, vol. 11674, pp. 33–47. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-30806-3_4
Burger, A.P., Cockayne, E.J., Gründlingh, W.R., Mynhardt, C.M., van Vuuren, J.H., Winterbach, W.: Infinite order domination in graphs. J. Combin. Math. Combin. Comput. 50, 179–194 (2004)
Cockayne, E.J., Dreyer Jr., P.A., Hedetniemi, S.M., Hedetniemi, S.T.: Roman domination in graphs. Discrete Math. 278(1–3), 11–22 (2004)
Diestel, R.: Graph Theory. GTM, vol. 173. Springer, Heidelberg (2017). https://doi.org/10.1007/978-3-662-53622-3
Dinur, I., Safra, S.: On the hardness of approximating minimum vertex cover. Ann Math (2) 162(1), 439–485 (2005)
Escoffier, B., Gourvès, L., Monnot, J.: Complexity and approximation results for the connected vertex cover problem in graphs and hypergraphs. J. Discrete Algorithms 8(1), 36–49 (2010)
Fernau, H., Manlove, D.F.: Vertex and edge covers with clustering properties: complexity and algorithms. J. Discrete Algorithms 7(2), 149–167 (2009)
Fomin, F.V., Gaspers, S., Golovach, P.A., Kratsch, D., Saurabh, S.: Parameterized algorithm for eternal vertex cover. Inf. Process. Lett. 110(16), 702–706 (2010)
Garey, M.R., Johnson, D.S.: The rectilinear Steiner tree problem is NP-complete. SIAM J. Appl. Math. 32(4), 826–834 (1977)
Goddard, W., Hedetniemi, S.M., Hedetniemi, S.T.: Eternal security in graphs. J. Combin. Math. Combin. Comput. 52, 169–180 (2005)
Goldwasser, J.L., Klostermeyer, W.F.: Tight bounds for eternal dominating sets in graphs. Discrete Math. 308(12), 2589–2593 (2008)
Klostermeyer, W.F.: An eternal vertex cover problem. J. Combin. Math. Combin. Comput. 85, 79–95 (2013)
Klostermeyer, W.F., MacGillivray, G.: Eternal dominating sets in graphs. J. Combin. Math. Combin. Comput. 68, 97–111 (2009)
Klostermeyer, W.F., Mynhardt, C.M.: Edge protection in graphs. Australas. J. Combin. 45, 235–250 (2009)
Klostermeyer, W.F., Mynhardt, C.M.: Graphs with equal eternal vertex cover and eternal domination numbers. Discrete Math. 311(14), 1371–1379 (2011)
Klostermeyer, W.F., Mynhardt, C.M.: Eternal total domination in graphs. Ars Combin. 107, 473–492 (2012)
Li, Y., Wang, W., Yang, Z.: The connected vertex cover problem in \(k\)-regular graphs. J. Comb. Optim. 38(2), 635–645 (2019). https://doi.org/10.1007/s10878-019-00403-3
Priyadarsini, P.L.K., Hemalatha, T.: Connected vertex cover in 2-connected planar graph with maximum degree 4 is NP-complete. Int. J. Math. Phys. Eng. Sci. 2(1), 51–54 (2008)
Savage, C.: Depth-first search and the vertex cover problem. Inform. Process. Lett. 14(5), 233–235 (1982)
Ueno, S., Kajitani, Y., Gotoh, S.: On the nonseparating independent set problem and feedback set problem for graphs with no vertex degree exceeding three. Discrete Math. 72, 355–360 (1988)
Watanabe, T., Kajita, S., Onaga, K.: Vertex covers and connected vertex covers in 3-connected graphs. In: IEEE International Symposium on Circuits and Systems, pp. 1017–1020 (1991)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Switzerland AG
About this paper
Cite this paper
Fujito, T., Nakamura, T. (2020). Eternal Connected Vertex Cover Problem. In: Chen, J., Feng, Q., Xu, J. (eds) Theory and Applications of Models of Computation. TAMC 2020. Lecture Notes in Computer Science(), vol 12337. Springer, Cham. https://doi.org/10.1007/978-3-030-59267-7_16
Download citation
DOI: https://doi.org/10.1007/978-3-030-59267-7_16
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-59266-0
Online ISBN: 978-3-030-59267-7
eBook Packages: Computer ScienceComputer Science (R0)