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Approximation Algorithms for Vertex-Connectivity Augmentation on the Cycle

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Approximation and Online Algorithms (WAOA 2021)

Abstract

Given a k-vertex-connected graph G and a set S of extra edges (links), the goal of the k-vertex-connectivity augmentation problem is to find a subset \(S'\) of S of minimum size such that adding \(S'\) to G makes it \((k+1)\)-vertex-connected. Unlike the edge-connectivity augmentation problem, research for the vertex-connectivity version has been sparse.

In this work we present the first polynomial time approximation algorithm that improves the known ratio of 2 for 2-vertex-connectivity augmentation, for the case in which G is a cycle. This is the first step for attacking the more general problem of augmenting a 2-connected graph.

Our algorithm is based on local search and attains an approximation ratio of 1.8703. To derive it, we prove novel results on the structure of minimal solutions.

Waldo Gálvez is supported by the European Research Council, Grant Agreement No. 691672, project APEG. Francisco Sanhueza-Matamala is partially supported by grants ANID-PFCHA/Magíster Nacional/2020- 22201780 and FONDECYT Regular 1190043. Francisco Sanhueza-Matamala and José A. Soto are partially supported by ANID via FONDECYT Regular 1181180 and PIA AFB170001.

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Notes

  1. 1.

    For \(k\in \mathbb {N}\), a k-connected graph is a graph \(G=(V,E)\) satisfying that, for any \(V'\subseteq V\) with \(|V|\le k-1\), G remains connected after the deletion of \(V'\). If the definition holds when replacing nodes by edges, the graph is said to be k-edge-connected.

  2. 2.

    A cactus is a 2-edge-connected graph where every edge belongs exactly to one cycle of the graph.

References

  1. Adjiashvili, D.: Beating approximation factor two for weighted tree augmentation with bounded costs. ACM Trans. Algorithms 15(2), 19:1–19:26 (2019). https://doi.org/10.1145/3182395

  2. Auletta, V., Dinitz, Y., Nutov, Z., Parente, D.: A 2-approximation algorithm for finding an optimum 3-vertex-connected spanning subgraph. J. Algorithms 32(1), 21–30 (1999). https://doi.org/10.1006/jagm.1999.1006

    Article  MathSciNet  MATH  Google Scholar 

  3. Basavaraju, M., Fomin, F.V., Golovach, P.A., Misra, P., Ramanujan, M.S., Saurabh, S.: Parameterized algorithms to preserve connectivity. In: Automata, Languages, and Programming - 41st International Colloquium, (ICALP). vol. 8572, pp. 800–811. Springer (2014). DOI: https://doi.org/10.1007/978-3-662-43948-7_66

  4. Byrka, J., Grandoni, F., Ameli, A.J.: Breaching the 2-approximation barrier for connectivity augmentation: a reduction to steiner tree. In: Proccedings of the 52nd Annual ACM SIGACT Symposium on Theory of Computing (STOC). pp. 815–825. ACM (2020). https://doi.org/10.1145/3357713.3384301

  5. Cecchetto, F., Traub, V., Zenklusen, R.: Bridging the gap between tree and connectivity augmentation: unified and stronger approaches. In: 53rd Annual ACM SIGACT Symposium on Theory of Computing (STOC). pp. 370–383. ACM (2021). https://doi.org/10.1145/3406325.3451086

  6. Cheriyan, J., Gao, Z.: Approximating (Unweighted) Tree Augmentation via Lift-and-Project, Part I: Stemless TAP. Algorithmica 80(2), 530–559 (2017). https://doi.org/10.1007/s00453-016-0270-4

    Article  MathSciNet  MATH  Google Scholar 

  7. Cheriyan, J., Jordán, T., Ravi, R.: On 2-coverings and 2-packings of laminar families. In: Algorithms - 7th Annual European Symposium (ESA). vol. 1643, pp. 510–520. Springer (1999). https://doi.org/10.1007/3-540-48481-7_44

  8. Cheriyan, J., Karloff, H.J., Khandekar, R., Könemann, J.: On the integrality ratio for tree augmentation. Oper. Res. Lett. 36(4), 399–401 (2008). https://doi.org/10.1016/j.orl.2008.01.009

    Article  MathSciNet  MATH  Google Scholar 

  9. Cohen, N., Nutov, Z.: A (1+ln2)-approximation algorithm for minimum-cost 2-edge-connectivity augmentation of trees with constant radius. Theor. Comput. Sci. 489–490, 67–74 (2013). https://doi.org/10.1016/j.tcs.2013.04.004

    Article  MATH  Google Scholar 

  10. Dinitz, E., Karnazov, A., Lomonosov, M.: On the structure of the system of minimum edge cuts of a graph. Studies in Discrete Optimization pp. 290–306 (1976)

    Google Scholar 

  11. Even, G., Feldman, J., Kortsarz, G., Nutov, Z.: A 1.8 approximation algorithm for augmenting edge-connectivity of a graph from 1 to 2. ACM Trans. Algorithms 5(2), 21:1–21:17 (2009). https://doi.org/10.1145/1497290.1497297

  12. Fiorini, S., Groß, M., Könemann, J., Sanità, L.: Approximating weighted tree augmentation via Chvátal-Gomory cuts. In: Proceedings of the Twenty-Ninth Annual ACM-SIAM Symposium on Discrete Algorithms (SODA). pp. 817–831. SIAM (2018). https://doi.org/10.1137/1.9781611975031.53

  13. Frederickson, G.N., JáJá, J.: Approximation algorithms for several graph augmentation problems. SIAM J. Comput. 10(2), 270–283 (1981). https://doi.org/10.1137/0210019

    Article  MathSciNet  MATH  Google Scholar 

  14. Gálvez, W., Grandoni, F., Jabal Ameli, A., Sornat, K.: On the Cycle Augmentation Problem: Hardness and Approximation Algorithms. Theory of Computing Systems 65(6), 985–1008 (2021). https://doi.org/10.1007/s00224-020-10025-6

    Article  MathSciNet  MATH  Google Scholar 

  15. Goemans, M.X., Goldberg, A.V., Plotkin, S.A., Shmoys, D.B., Tardos, É., Williamson, D.P.: Improved approximation algorithms for network design problems. In: Proceedings of the Fifth Annual ACM-SIAM Symposium on Discrete Algorithms (SODA). pp. 223–232. ACM/SIAM (1994), http://dl.acm.org/citation.cfm?id=314464.314497

  16. Grandoni, F., Kalaitzis, C., Zenklusen, R.: Improved approximation for tree augmentation: saving by rewiring. In: Proceedings of the 50th Annual ACM SIGACT Symposium on Theory of Computing (STOC). pp. 632–645. ACM (2018). https://doi.org/10.1145/3188745.3188898

  17. Khuller, S., Thurimella, R.: Approximation algorithms for graph augmentation. J. Algorithms 14(2), 214–225 (1993). https://doi.org/10.1006/jagm.1993.1010

    Article  MathSciNet  MATH  Google Scholar 

  18. Khuller, S., Vishkin, U.: Biconnectivity approximations and graph carvings. J. ACM 41(2), 214–235 (1994). https://doi.org/10.1145/174652.174654

    Article  MathSciNet  MATH  Google Scholar 

  19. Kortsarz, G., Krauthgamer, R., Lee, J.R.: Hardness of approximation for vertex-connectivity network design problems. SIAM J. Comput. 33(3), 704–720 (2004). https://doi.org/10.1137/S0097539702416736

    Article  MathSciNet  MATH  Google Scholar 

  20. Kortsarz, G., Nutov, Z.: A simplified 1.5-approximation algorithm for augmenting edge-connectivity of a graph from 1 to 2. ACM Trans. Algorithms 12(2), 23:1–23:20 (2016). https://doi.org/10.1145/2786981

  21. Kortsarz, G., Nutov, Z.: LP-relaxations for tree augmentation. Discret. Appl. Math. 239, 94–105 (2018). https://doi.org/10.1016/j.dam.2017.12.033

    Article  MathSciNet  MATH  Google Scholar 

  22. Mader, W.: Ecken vom gradn in minimalenn-fach zusammenhängenden graphen. Archiv der Mathematik 23(1), 219–224 (1972)

    Article  MathSciNet  Google Scholar 

  23. Marx, D., Végh, L.A.: Fixed-parameter algorithms for minimum-cost edge-connectivity augmentation. ACM Trans. Algorithms 11(4), 27:1–27:24 (2015). https://doi.org/10.1145/2700210

  24. Nagamochi, H.: An approximation for finding a smallest 2-edge-connected subgraph containing a specified spanning tree. Discret. Appl. Math. 126(1), 83–113 (2003). https://doi.org/10.1016/S0166-218X(02)00218-4

    Article  MathSciNet  MATH  Google Scholar 

  25. Nutov, Z.: 2-node-connectivity network design. CoRR abs/2002.04048 (2020), https://arxiv.org/abs/2002.04048

  26. Nutov, Z.: A \(4 + \varepsilon \) approximation for \(k\)-connected subgraphs. In: Proceedings of the 2020 ACM-SIAM Symposium on Discrete Algorithms (SODA). pp. 1000–1009. SIAM (2020). https://doi.org/10.1137/1.9781611975994.60

  27. Nutov, Z.: On the Tree Augmentation Problem. Algorithmica 83(2), 553–575 (2020). https://doi.org/10.1007/s00453-020-00765-9

    Article  MathSciNet  MATH  Google Scholar 

  28. Spinrad, J.P.: Recognition of circle graphs. J. Algorithms 16(2), 264–282 (1994). https://doi.org/10.1006/jagm.1994.1012

    Article  MathSciNet  MATH  Google Scholar 

  29. Traub, V., Zenklusen, R.: A better-than-2 approximation for weighted tree augmentation. CoRR abs/2104.07114 (2021), https://arxiv.org/abs/2104.07114

  30. Végh, L.A.: Augmenting undirected node-connectivity by one. SIAM J. Discret. Math. 25(2), 695–718 (2011). https://doi.org/10.1137/100787507

    Article  MathSciNet  MATH  Google Scholar 

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Gálvez, W., Sanhueza-Matamala, F., Soto, J.A. (2021). Approximation Algorithms for Vertex-Connectivity Augmentation on the Cycle. In: Koenemann, J., Peis, B. (eds) Approximation and Online Algorithms. WAOA 2021. Lecture Notes in Computer Science(), vol 12982. Springer, Cham. https://doi.org/10.1007/978-3-030-92702-8_1

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  • DOI: https://doi.org/10.1007/978-3-030-92702-8_1

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