Abstract
Given an undirected graph G = (V,E) and subset of terminals T ⊆ V, the element-connectivity κ′ G (u,v) of two terminals u,v ∈ T is the maximum number of u-v paths that are pairwise disjoint in both edges and non-terminals V ∖ T (the paths need not be disjoint in terminals). Element-connectivity is more general than edge-connectivity and less general than vertex-connectivity. Hind and Oellermann [18] gave a graph reduction step that preserves the global element-connectivity of the graph. We show that this step also preserves local connectivity, that is, all the pairwise element-connectivities of the terminals.
We give two applications of the step to connectivity and network design problems: First, we show a polylogarithmic approximation for the problem of packing element-disjoint Steiner forests in general graphs, and an O(1)-approximation in planar graphs. Second, we find a very short and intuitive proof of a spider-decomposition theorem of Chuzhoy and Khanna [10] in the context of the single-sink k-vertex-connectivity problem. Our results highlight the effectiveness of the element-connectivity reduction step; we believe it will find more applications in the future.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Aazami, A., Cheriyan, J., Jampani, K.R.: Approximation Algorithms and Hardness Results for Packing Element-Disjoint Steiner Trees. Algorithmica (manuscript submitted, 2008)
Calinescu, G., Chekuri, C., Vondrak, J.: Disjoint Bases in a Polymatroid. Random Structures & Algorithms (to appear)
Chakraborty, T., Chuzhoy, J., Khanna, S.: Network Design for Vertex Connectivity. In: Proc. of ACM STOC, pp. 167–176 (2008)
Chekuri, C., Korula, N.: Single-Sink Network Design with Vertex-Connectivity Requirements. In: Proc. of FST&TCS (2008)
Chekuri, C., Shepherd, B.: Approximate Integer Decompositions for Undirected Network Design Problems. SIAM J. on Disc. Math. 23(1), 163–177 (2008)
Cheriyan, J.: Personal Communication (October 2008)
Cheriyan, J., Salavatipour, M.: Hardness and Approximation Results for Packing Steiner Trees. Algorithmica 45(1), 21–43 (2006)
Cheriyan, J., Salavatipour, M.: Packing Element-disjoint Steiner Trees. ACM Trans. on Algorithms 3(4) (2007)
Cheriyan, J., Vempala, S., Vetta, A.: Network design via iterative rounding of setpair relaxations. Combinatorica 26(3), 255–275 (2006)
Chuzhoy, J., Khanna, S.: Algorithms for Single-Source Vertex-Connectivity. In: Proc. of IEEE FOCS, pp. 105–114 (October 2008)
Chuzhoy, J., Khanna, S.: An O(k3 logn)-Approximation Algorithm for Vertex-Connectivity Survivable Network Design, arXiv.org preprint. arXiv:0812.4442v1
Feige, U., Halldórsson, M., Kortsarz, G., Srinivasan, A.: Approximating the Domatic Number. SIAM J. Comput. 32(1), 172–195 (2002)
Fleischer, L., Jain, K., Williamson, D.P.: Iterative Rounding 2-approximation Algorithms for Minimum-cost Vertex Connectivity Problems. J. of Computer and System Sciences 72(5), 838–867 (2006)
Frank, A.: On Connectivity Properties of Eulerian Digraphs. Annals of Discrete Mathematics 41, 179–194 (1989)
Frank, A.: Augmenting graphs to meet edge-connectivity requirements. SIAM J. on Discrete Math. 5(1), 22–53 (1992)
Frank, A., Király, T., Kriesell, M.: On decomposing a hypergraph into k connected sub-hypergraphs. Discr. Applied Math. 131(2), 373–383 (2003)
Grötschel, M., Martin, A., Weismantel, R.: The Steiner tree packing problem in VLSI-design. Math. Programming 78, 265–281 (1997)
Hind, H.R., Oellermann, O.: Menger-type results for three or more vertices. Congressus Numerantium 113, 179–204 (1996)
Jain, K.: A factor 2 approximation algorithm for the generalized Steiner network problem. Combinatorica 21(1), 39–60 (2001)
Jain, K., Mahdian, M., Salavatipour, M.: Packing Steiner Trees. In: Proc. of ACM-SIAM SODA, pp. 266–274 (2003)
Jain, K., Mandoiu, I.I., Vazirani, V.V., Williamson, D.P.: A Primal-Dual Schema Based Approximation Algorithm for the Element Connectivity Problem. In: Proc. of ACM-SIAM SODA, pp. 484–489 (1999)
Jackson, B.: Some Remarks on Arc-connectivity, Vertex splitting, and Orientation in Digraphs. Journal of Graph Theory 12(3), 429–436 (1998)
Király, T., Lau, L.C.: Approximate Min-Max Theorems of Steiner Rooted-Orientations of Hypergraphs. J. of Combin. Theory B 98(6), 1233–1252 (2008)
Kortsarz, G., Krauthgamer, R., Lee, J.R.: Hardness of Approximation for Vertex-Connectivity Network Design Problems. SIAM J. Comput. 33(3), 704–720 (2004)
Kortsarz, G., Nutov, Z.: Approximating min-cost connectivity problems. In: Handbook on Approx. Algorithms and Metaheuristics, CRC Press, Boca Raton (2006)
Kriesell, M.: Edge-disjoint trees containing some given vertices in a graph. J. of Combin. Theory B 88, 53–63 (2003)
Lau, L.C.: An approximate max-Steiner-tree-packing min-Steiner-cut theorem. Combinatorica 27(1), 71–90 (2007)
Lau, L.C.: Packing steiner forests. In: Jünger, M., Kaibel, V. (eds.) IPCO 2005. LNCS, vol. 3509, pp. 362–376. Springer, Heidelberg (2005)
Lovász, L.: On some connectivity properties of Eulerian graphs. Acta Math. Hung. 28, 129–138 (1976)
Mader, W.: A reduction method for edge connectivity in graphs. Ann. Discrete Math. 3, 145–164 (1978)
Nutov, Z.: An almost O(logk)-approximation for k-connected subgraphs. In: Proc. of ACM-SIAM SODA, pp. 912–921 (2009)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2009 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Chekuri, C., Korula, N. (2009). A Graph Reduction Step Preserving Element-Connectivity and Applications. In: Albers, S., Marchetti-Spaccamela, A., Matias, Y., Nikoletseas, S., Thomas, W. (eds) Automata, Languages and Programming. ICALP 2009. Lecture Notes in Computer Science, vol 5555. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-02927-1_22
Download citation
DOI: https://doi.org/10.1007/978-3-642-02927-1_22
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-02926-4
Online ISBN: 978-3-642-02927-1
eBook Packages: Computer ScienceComputer Science (R0)