Abstract
The Contractibility problem takes as input two graphs G and H, and the task is to decide whether H can be obtained from G by a sequence of edge contractions. The Induced Minor and Induced Topological Minor problems are similar, but the first allows both edge contractions and vertex deletions, whereas the latter allows only vertex deletions and vertex dissolutions. All three problems are NP-complete, even for certain fixed graphs H. We show that these problems can be solved in polynomial time for every fixed H when the input graph G is chordal. Our results can be considered tight, since these problems are known to be W[1]-hard on chordal graphs when parameterized by the size of H. To solve Contractibility and Induced Minor, we define and use a generalization of the classic Disjoint Paths problem, where we require the vertices of each of the k paths to be chosen from a specified set. We prove that this variant is NP-complete even when k=2, but that it is polynomial-time solvable on chordal graphs for every fixed k. Our algorithm for Induced Topological Minor is based on another generalization of Disjoint Paths called Induced Disjoint Paths, where the vertices from different paths may no longer be adjacent. We show that this problem, which is known to be NP-complete when k=2, can be solved in polynomial time on chordal graphs even when k is part of the input. Our results fit into the general framework of graph containment problems, where the aim is to decide whether a graph can be modified into another graph by a sequence of specified graph operations. Allowing combinations of the four well-known operations edge deletion, edge contraction, vertex deletion, and vertex dissolution results in the following ten containment relations: (induced) minor, (induced) topological minor, (induced) subgraph, (induced) spanning subgraph, dissolution, and contraction. Our results, combined with existing results, settle the complexity of each of the ten corresponding containment problems on chordal graphs.
Similar content being viewed by others
References
Belmonte, R., Golovach, P.A., Heggernes, P., van ’t Hof, P., Kamiński, M., Paulusma, D.: Finding contractions and induced minors in chordal graphs via disjoint paths. In: Proceedings of ISAAC 2011. LNCS, vol. 7074, pp. 110–119. Springer, Berlin (2011)
Belmonte, R., Heggernes, P., van ’t Hof, P.: Edge contractions in subclasses of chordal graphs. In: Proceedings of TAMC 2011. LNCS, vol. 6648, pp. 528–539. Springer, Berlin (2011)
Bienstock, D.: On the complexity of testing for odd holes and induced odd paths. Discrete Math. 90, 85–92 (1991). See also Corrigendum. Discrete Math. 102, 109 (1992)
Blair, J.R.S., Peyton, B.W.: An introduction to chordal graphs and clique trees. In: Graph Theory and Sparse Matrix Computations. IMA Volumes in Mathematics and Its Applications, vol. 56, pp. 1–29. Springer, Berlin (1993)
Booth, K.S., Lueker, G.S.: Testing for the consecutive ones property, interval graphs, and graph planarity using PQ-tree algorithms. J. Comput. Syst. Sci. 13, 335–379 (1976)
Brandstädt, A., Le, V.B., Spinrad, J.P.: Graph Classes: A Survey. SIAM, Philadelphia (1999)
Brouwer, A.E., Veldman, H.J.: Contractibility and NP-completeness. J. Graph Theory 11, 71–79 (1987)
Courcelle, B.: The monadic second-order logic of graphs. I. Recognizable sets of finite graphs. Inf. Comput. 85, 12–75 (1990)
Dirac, G.A.: On rigid circuit graphs. Abh. Math. Semin. Univ. Hamb. 25, 71–76 (1961)
Downey, R.G., Fellows, M.R.: Fixed-parameter tractability and completeness II: On completeness for W[1]. Theor. Comput. Sci. 141, 109–131 (1995)
Fiala, J., Kamiński, M., Lidický, B., Paulusma, D.: The k-in-a-path problem for claw-free graphs. Algorithmica 62, 499–519 (2012)
Fiala, J., Kamiński, M., Paulusma, D.: A note on contracting claw-free graphs. Manuscript (2011)
Fellows, M.R., Kratochvíl, J., Middendorf, M., Pfeiffer, F.: The complexity of induced minors and related problems. Algorithmica 13, 266–282 (1995)
Flum, J., Grohe, M.: Parameterized Complexity Theory. Springer, Berlin (2006)
Garey, M.R., Johnson, D.S.: Computers and Intractability: A Guide to the Theory of NP-Completeness. Freeman, New York (1979)
Gavril, F.: The intersection graphs of subtrees in trees are exactly the chordal graphs. J. Comb. Theory, Ser. B 16, 47–56 (1974)
George, A., Liu, J.W.: Computer Solutions of Large Sparse Positive Definite Systems. Prentice Hall, New York (1981)
Golovach, P.A., Kamiński, M., Paulusma, D.: Contracting a chordal graph to a split graph or a tree. In: Proceedings of MFCS 2011. LNCS, vol. 6907, pp. 339–350. Springer, Berlin (2011)
Golovach, P.A., Kamiński, M., Paulusma, D., Thilikos, D.M.: Containment relations in split graphs. Discrete Appl. Math. 160, 155–163 (2012)
Golumbic, M.C.: Algorithmic Graph Theory and Perfect Graphs. Annals of Discrete Mathematics, vol. 57. Elsevier, Amsterdam (2004)
Grohe, M., Kawarabayashi, K., Marx, D., Wollan, P.: Finding topological subgraphs is fixed-parameter tractable. In: Proceedings of STOC 2011, pp. 479–488 (2011)
van ’t Hof, P., Kamiński, M., Paulusma, D., Szeider, S., Thilikos, D.M.: On graph contractions and induced minors. Discrete Appl. Math. 160, 799–809 (2012)
van ’t Hof, P., Paulusma, D., Woeginger, G.J.: Partitioning graphs in connected parts. Theor. Comput. Sci. 410, 4834–4843 (2009)
Kamiński, M., Thilikos, D.M.: Contraction checking in graphs on surfaces. In: Proceedings of STACS, 2012, to appear
Kloks, T.: Treewidth, Computations and Approximations. LNCS, vol. 842. Springer, Berlin (1994)
Lévêque, B., Lin, D.Y., Maffray, F., Trotignon, N.: Detecting induced subgraphs. Discrete Appl. Math. 157, 3540–3551 (2009)
Levin, A., Paulusma, D., Woeginger, G.J.: The computational complexity of graph contractions I: polynomially solvable and NP-complete cases. Networks 51, 178–189 (2008)
Levin, A., Paulusma, D., Woeginger, G.J.: The computational complexity of graph contractions II: two tough polynomially solvable cases. Networks 52, 32–56 (2008)
Matoušek, J., Thomas, R.: On the complexity of finding iso- and other morphisms for partial k-trees. Discrete Math. 108, 343–364 (1992)
Natarajan, S., Sprague, A.P.: Disjoint paths in circular arc graphs. Nord. J. Comput. 3, 256–270 (1996)
Niedermeier, R.: Invitation to Fixed-Parameter Algorithms. Oxford University Press, Oxford (2006)
de Ridder, H.N., et al.: Information System on Graph Classes and their Inclusions (ISGCI). http://www.graphclasses.org, 2001–2012
Robertson, N., Seymour, P.D.: Graph minors. XIII. The disjoint paths problem. J. Comb. Theory, Ser. B 63, 65–110 (1995)
Semple, C., Steel, M.: Phylogenetics. Oxford Lecture Series in Mathematics and Its Applications. Oxford University Press, Oxford (2003)
Tarjan, R.E., Yannakakis, M.: Simple linear-time algorithms to test chordality of graphs, test acyclicity of hypergraphs, and selectively reduce acyclic hypergraphs. SIAM J. Comput. 13, 66–579 (1984)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Belmonte, R., Golovach, P.A., Heggernes, P. et al. Detecting Fixed Patterns in Chordal Graphs in Polynomial Time. Algorithmica 69, 501–521 (2014). https://doi.org/10.1007/s00453-013-9748-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00453-013-9748-5