Abstract
Motivated by applications in network epidemiology, we consider the problem of determining whether it is possible to delete at most k edges from a given input graph (of small treewidth) so that the resulting graph avoids a set \(\mathcal {F}\) of forbidden subgraphs; of particular interest is the problem of determining whether it is possible to delete at most k edges so that the resulting graph has no connected component of more than h vertices, as this bounds the worst-case size of an epidemic. While even this special case of the problem is NP-complete in general (even when \(h=3\)), we provide evidence that many of the real-world networks of interest are likely to have small treewidth, and we describe an algorithm which solves the general problem in time \(2^{O(|\mathcal {F}|w^r)}n\) on an input graph having n vertices and whose treewidth is bounded by a fixed constant w, if each of the subgraphs we wish to avoid has at most r vertices. For the special case in which we wish only to ensure that no component has more than h vertices, we improve on this to give an algorithm running in time \(O((wh)^{2w}n)\), which we have implemented and tested on real datasets based on cattle movements.
Similar content being viewed by others
Notes
Available at treewidth.com/treewidth/index.html.
References
Anderson, R., Gupta, S., Ng, W.: The significance of sexual partner contact networks for the transmission dynamics of HIV. J. Acquir. Immune Defic. Syndr. Hum. Retrovirol. 3, 417–429 (1990)
Arnborg, S., Corneil, D.G., Proskurowski, A.: Complexity of finding embeddings in a \(k\)-tree. SIAM J. Alg. Disc. Methods 8, 277–284 (1987)
Arnborg, S., Lagergren, J., Sesse, D.: Easy problems for tree-decomposable graphs. J. Algorithms 12, 308–340 (1991)
Bodlaender, H.L.: A linear time algorithm for finding tree-decompositions of small treewidth. In: Proceedings of the Twenty-Fifth Annual ACM Symposium on Theory of Computing, STOC ’93, pp. 226–234. ACM, New York (1993). doi:10.1145/167088.167161
Cai, L.: Fixed-parameter tractability of graph modification problems for hereditary properties. Inf. Process. Lett. 58(4), 171–176 (1996). doi:10.1016/0020-0190(96)00050-6
Courcelle, B., Mosbah, M.: Monadic second-order evaluations on tree-decomposable graphs. Theor. Comput. Sci. 109(12), 49–82 (1993). doi:10.1016/0304-3975(93)90064-Z
Drange, P.G., Dregi, M.S., van ’t Hof, P.: On the computational complexity of vertex integrity and component order connectivity. In: Ahn, H.K., Shin, C.S. (eds.) Algorithms and Computation. Lecture Notes in Computer Science, pp. 285–297. Springer International Publishing, Berlin (2014). doi:10.1007/978-3-319-13075-023
El-Mallah, E.S., Colbourn, C.J.: The complexity of some edge deletion problems. IEEE Trans. Circuits Syst. 3, 354–362 (1988)
Gao, Y.: Treewidth of Erdős–Renyi random graphs, random intersection graphs, and scale-free random graphs. Discret. Appl. Math. 160(45), 566–578 (2012). doi:10.1016/j.dam.2011.10.013
Garey, M.R., Johnson, D.S.: Computers and Intractability: A Guide to the Theory of NP-Completeness. W. H. Freeman & Co., New York (1979)
Gecode Team: Gecode: Generic constraint development environment (2016). http://www.gecode.org
Ghosh, E., Kolay, S., Kumar, M., Misra, P., Panolan, F., Rai, A., Ramanujan, M.: Faster parameterized algorithms for deletion to split graphs. In: Fomin, F., Kaski, P. (eds.) Algorithm Theory SWAT 2012. Lecture Notes in Computer Science, pp. 107–118. Springer, Berlin (2012). doi:10.1007/978-3-642-31155-010
Goldberg, P.W., Golumbic, M.C., Kaplan, H., Shamir, R.: Four strikes against physical mapping of DNA. J. Comput. Biol. 2, 139–152 (1993)
Golumbic, M.C.: Algorithmic Graph Theory and Perfect Graphs, vol. 57. Elsevier, Amsterdam (2004)
Gross, D., Heinig, M., Iswara, L., Kazmierczak, L.W., Luttrell, K., Saccoman, J.T., Suffel, C.: A survey of component order connectivity models of graph theoretic networks. SWEAS Trans. Math. 12(9), 895–910 (2013)
Guo, J.: Problem kernels for NP-complete edge deletion problems: split and related graphs. In: Tokuyama, T. (ed.) Algorithms and Computation. Lecture Notes in Computer Science, vol. 4835, pp. 915–926. Springer, Berlin (2007). doi:10.1007/978-3-540-77120-379
Kao, R.R., Green, D.M., Johnson, J., Kiss, I.Z.: Disease dynamics over very different time-scales: foot-and-mouth disease and scrapie on the network of livestock movements in the UK. J. R. Soc. Interface 4(16), 907–916 (2007). doi:10.1098/rsif.2007.1129
Kloks, T., Treewidth, T.: Computations and Approximations. Lecture Notes in Computer Science. Springer, Berlin (1994). doi:10.1007/BFb0045375
Lewis, J.M., Yannakakis, M.: The node-deletion problem for hereditary properties is NP-complete. J. Comput. Syst. Sci. 20(2), 219–230 (1980). doi:10.1016/0022-0000(80)90060-4
Li, A., Tang, L.: The complexity and approximability of minimum contamination problems. In: Ogihara, M., Tarui, J. (eds.) Theory and Applications of Models of Computation. Lecture Notes in Computer Science, vol. 6648, pp. 298–307. Springer, Berlin (2011). doi:10.1007/978-3-642-20877-5_30
Margot, F.: Some complexity results about threshold graphs. Discret. Appl. Math. 49(1:3), 299–308 (1994). doi:10.1016/0166-218X(94)90214-3
Mitchell, A., Bourn, D., Mawdsley, J., Wint, W., Clifton-Hadley, R., Gilbert, M.: Characteristics of cattle movements in britain: an analysis of records from the cattle tracing system. Anim. Sci. 80, 265–273 (2005). doi:10.1079/ASC50020265
Natanzon, A., Shamir, R., Sharan, R.: Complexity classification of some edge modification problems. Discret. Appl. Math. 113(1), 109–128 (2001). doi:10.1016/S0166-218X(00)00391-7
Nethercote, N., Stuckey, P.J., Becket, R., Brand, S., Duck, G.J., Tack, G.: MiniZinc: towards a standard CP modelling language. In: Proceedings of the 13th International Conference on Principles and Practice of Constraint Programming. CP’07, pp. 529–543. Springer, Berlin (2007)
Prud’homme, C., Fages, J-G., Lorca, X.: Choco documentation (2016). http://www.choco-solver.org
Robertson, N., Seymour, P.: Graph minors. III. planar tree-width. J. Comb. Theory Ser. B 36(1), 49–64 (1984). doi:10.1016/0095-8956(84)90013-3. http://www.sciencedirect.com/science/article/pii/0095895684900133
Schulte, C., Tack, G., Lagerkvist, M.Z.: Modeling and programming with Gecode (2013). http://www.gecode.org
Stuckey, P.J., Feydy, T., Schutt, A., Tack, G., Fischer, J.: The minizinc challenge 2008–2013. AI Mag. 35(2), 55–60 (2014)
van Dijk, T., van den Heuvel, J.P., Slob, W.: Computing treewidth with LibTW (2006)
Watanabe, T., Ae, T., Nakamura, A.: On the NP-hardness of edge-deletion and -contraction problems. Discret. Appl. Math. 6(1), 63–78 (1983). doi:10.1016/0166-218X(83)90101-4
Yannakakis, M.: Node-and edge-deletion NP-complete problems. In: Proceedings of the Tenth Annual ACM Symposium on Theory of Computing, STOC ’78, pp. 253–264. ACM, New York (1978). doi:10.1145/800133.804355
Acknowledgements
The authors would like to thank the following: Ivaylo Valkov for his assistance in developing an initial implementation of this algorithm as part of a summer research project, and the Engineering and Physical Sciences Research Council for providing funding for this summer project; EPIC: Scotland’s Centre of Expertise on Animal Disease Outbreaks, which supported JE for part of her work on this project; the Royal Society of Edinburgh which supported KM for part of her work on this project through a Personal Research Fellowship funded by the Scottish Government; Ciaran McCreesh and Patrick Prosser for their assistance in developing the CP formulation against which we compared the performance of our algorithm.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Enright, J., Meeks, K. Deleting Edges to Restrict the Size of an Epidemic: A New Application for Treewidth. Algorithmica 80, 1857–1889 (2018). https://doi.org/10.1007/s00453-017-0311-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00453-017-0311-7