Abstract
We present a greedy algorithm for the directed Steiner tree problem (DST), where any tree rooted at any (uncovered) terminal can be a candidate for greedy choice. It will be shown that the algorithm, running in polynomial time for any constant \(l\), outputs a directed Steiner tree of cost no larger than \(2(l-1)(\ln n+1)\) times the cost of any \(l\)-restricted Steiner tree, which is such a Steiner tree in which every terminal is at most \(l\) arcs away from the root or another terminal. We derive from this result that (1) DST for a class of graphs, including quasi-bipartite graphs, in which the length of paths induced by Steiner vertices is bounded by some constant can be approximated within a factor of \(O(\log n)\), and (2) the tree cover problem on directed graphs can also be approximated within a factor of \(O(\log n)\).
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References
Berman, P., Ramaiyer, V.: Improved approximations for the Steiner tree problem. J. Algorithms 17(3), 381–408 (1994)
Byrka, J., Grandoni, F., Rothvoss, T., Sanità, L.: Steiner tree approximation via iterative randomized rounding. J. ACM 60(1), 6:1–6:33 (2013)
Calinescu, G., Zelikovsky, A.: The polymatroid Steiner problems. J. Comb. Optim. 9, 281–294 (2005)
Charikar, M., Chekuri, C., Cheung, T., Dai, Z., Goel, A., Guha, S., Li, M.: Approximation algorithms for directed Steiner tree problems. J. Algorithms 33, 73–91 (1999)
Chlebík, M., Chlebíková, J.: The Steiner tree problem on graphs: inapproximability results. Theor. Comput. Sci. 406(3), 207–214 (2008)
Feige, U.: A threshold of \(\ln n\) for approximating set cover. J. ACM 45(4), 634–652 (1998)
Fujito, T.: How to trim a MST: a 2-approximation algorithm for minimum cost tree cover. ACM Trans. Algorithms 8(2), 16:1–16:11 (2012)
Halperin, E., Krauthgamer, R.: Polylogarithmic inapproximability. In: Proceedings of the 35th Symposium on Theory of Computing, pp. 585–594. (2003)
Karp, R.M.: Reducibility among combinatorial problems. In: Complexity of Computer Computations, pp. 85–103. Plenum Press, New York (1972)
Karpinski, M., Zelikovsky, A.Z.: New approximation algorithms for the Steiner tree problem. J. Combin. Optim. 1, 47–65 (1997)
Könemann, J., Konjevod, G., Parekh, O., Sinha, A.: Improved approximations for tour and tree covers. Algorithmica 38(3), 441–449 (2004)
Konjevod, G.: Directed Steiner trees, linear programs and randomized rounding. Manuscript, 8 pages (2005)
Kortsarz, G., Peleg, D.: Approximating the weight of shallow Steiner trees. Discrete Appl. Math. 93, 265–285 (1999)
Rajagopalan, S., Vazirani, V.V.: On the bidirected cut relaxation for the metric Steiner tree problem. In: Proceedings of the 10th Symposium on Discrete Algorithms, pp. 742–751. (1999)
Raz, R., Safra, S.: A sub-constant error-probability low-degree test, and a sub-constant error-probability PCP characterization of NP. In: Proceedings of the 29th Symposium on Theory of Computing, pp. 475–484. (1997)
Robins, G., Zelikovsky, A.: Tighter bounds for graph Steiner tree approximation. SIAM J. Discrete Math. 19, 122–134 (2005)
Rothvoß, T.: Directed Steiner tree and the Lasserre hierarchy. arXiv:1111.5473 (2011)
Savage, C.: Depth-first search and the vertex cover problem. Inf. Process. Lett. 14(5), 233–235 (1982)
Zelikovsky, A.: An 11/6-approximation algorithm for the network Steiner problem. Algorithmica 9, 463–470 (1993)
Zelikovsky, A.: A series of approximation algorithms for the acyclic directed Steiner tree problem. Algorithmica 18, 99–110 (1997)
Zosin, L., Khuller, S.: On directed Steiner trees. In: Proceedings of the 13th Symposium on Discrete Algorithms, pp. 59–63. (2002)
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A preliminary version of this work appeared in Proceedings of 38th WG (International Workshop on Graph Theoretic Concepts in Computer Science), 2012. Supported in part by the Kayamori Foundation of Informational Science Advancement and a Grant in Aid for Scientific Research of the Ministry of Education, Science, Sports and Culture of Japan.
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Hibi, T., Fujito, T. Multi-rooted Greedy Approximation of Directed Steiner Trees with Applications. Algorithmica 74, 778–786 (2016). https://doi.org/10.1007/s00453-015-9973-1
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DOI: https://doi.org/10.1007/s00453-015-9973-1