Abstract
We consider Degree Constrained Survivable Network problems. For the directed Degree Constrained k -Edge-Outconnected Subgraph problem, we slightly improve the best known approximation ratio, by a simple proof. Our main contribution is giving a framework to handle node-connectivity degree constrained problems with the iterative rounding method. In particular, for the degree constrained versions of the Element-Connectivity Survivable Network problem on undirected graphs, and of the k -Outconnected Subgraph problem on both directed and undirected graphs, our algorithm computes a solution J of cost O(logk) times the optimal, with degrees O(2k)⋅b(v). Similar result are obtained for the k -Connected Subgraph problem. The latter improves on the only degree approximation O(klogn)⋅b(v) in O(n k) time on undirected graphs by Feder, Motwani, and Zhu.
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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)
Bansal, N., Khandekar, R., Nagarajan, V.: Additive guarantees for degree bounded directed network design. SIAM J. Comput. 39(4), 1413–1431 (2009)
Chan, Y., Fung, W., Lau, L., Yung, C.: Degree bounded network design with metric costs. SIAM J. Comput. 40(4), 953–980 (2011)
Cheriyan, J., Vempala, S., Vetta, A.: Network design via iterative rounding of setpair relaxations. Combinatorica 26(3), 255–275 (2006)
Chuzhoy, J., Khanna, S.: An O(k 3logn)-approximation algorithm for vertex-connectivity survivable network design. In: FOCS, pp. 437–441 (2009)
Feder, T., Motwani, R., Zhu, A.: k-connected spanning subgraphs of low degree. Electron. Colloq. Comput. Complex. 13, 041 (2006)
Fleischer, L., Jain, K., Williamson, D.: Iterative rounding 2-approximation algorithms for minimum-cost vertex connectivity problems. J. Comput. Syst. Sci. 72(5), 838–867 (2006)
Frank, A.: Rooted k-connections in digraphs. Discrete Appl. Math. 157, 1242–1254 (2009)
Frank, A., Jordán, T.: Minimal edge-coverings of pairs of sets. J. Comb. Theory, Ser. B 65(1), 73–110 (1995)
Frank, A., Tardos, E.: An application of submodular flows. Linear Algebra Appl. 114/115, 329–348 (1989)
Fukunaga, T., Nagamochi, H.: Network design with weighted degree constraints. Discrete Optim. 7(4), 246–255 (2010)
Fukunaga, T., Ravi, R.: Iterative rounding approximation algorithms for degree-bounded node-connectivity network design. In: FOCS, pp. 263–272 (2012)
Fukunaga, T., Nutov, Z., Ravi, R.: Iterative rounding approximation algorithms for degree-bounded node-connectivity problems. Manuscript
Jain, K.: A factor 2 approximation algorithm for the generalized Steiner network problem. Combinatorica 21(1), 39–60 (2001)
Khandekar, R., Kortsarz, G., Nutov, Z.: Network-design with degree constraints. In: APPROX, pp. 289–301 (2011)
Khuller, S., Raghavachari, B.: Improved approximation algorithms for uniform connectivity problems. J. Algorithms 21, 434–450 (1996)
Kortsarz, G., Nutov, Z.: Approximating node connectivity problems via set covers. Algorithmica 37, 75–92 (2003)
Lau, L., Singh, M.: Additive approximation for bounded degree survivable network design. In: STOC, pp. 759–768 (2008)
Lau, L., Naor, J., Salavatipour, M., Singh, M.: Survivable network design with degree or order constraints. SIAM J. Comput. 39(3), 1062–1087 (2009)
Lau, L.C., Ravi, R., Singh, M.: Iterative Methods in Combinatorial Optimization. Cambridge University Press, Cambridge (2011)
Louis, A., Vishnoi, N.: Improved algorithm for degree bounded survivable network design problem. In: SWAT, pp. 408–419 (2010)
Nutov, Z.: Approximating minimum-cost edge-covers of crossing biset families (2010). Manuscript. Preliminary version in SODA 2009, pp. 912–921
Nutov, Z.: Approximating directed weighted-degree constrained networks. Theor. Comput. Sci. 408(8–10), 901–912 (2011)
Nutov, Z.: Approximating minimum cost connectivity problems via uncrossable bifamilies (2011). Manuscript. Preliminary version FOCS 2010, pp. 417–426
Nutov, Z.: Degree-constrained node-connectivity. In: LATIN, pp. 582–593 (2012)
Singh, M., Lau, L.: Approximating minimum bounded degree spanning trees to within one of optimal. In: STOC, pp. 661–670 (2007)
Acknowledgements
I thank Jochen Könemann for drawing my attention that no non-trivial algorithm was known for Degree Constrained Element-Connectivity Survivable Network problem. I also thank Rohit Khandekar and Guy Kortsarz for some discussions.
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Nutov, Z. Degree Constrained Node-Connectivity Problems. Algorithmica 70, 340–364 (2014). https://doi.org/10.1007/s00453-013-9849-1
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DOI: https://doi.org/10.1007/s00453-013-9849-1