Abstract
Consider the following kDSP problem: given a graph G and k pairs of terminal vertices \((s_1, t_1), (s_2, t_2), \ldots , (s_k, t_k)\), check if there exists a k-tuple of pairwise disjoint shortest \(s_i\)–\(t_i\) paths between these k pairs of terminal vertices. Algorithmically, the case of two vertex-disjoint paths turns out to be the most interesting one. For this setting, Eilam-Tzoreff established an algorithm running in \(\mathcal {O}(|V|^8)\) time, which uses dynamic programming (DP) and applies to both directed and undirected graphs and arbitrary positive edge weights (lengths). In this paper, we examine the DP relations arising in this problem and reduce the time complexity to \(\mathcal {O}(|V|^6)\) for the unit-length case and to \(\mathcal {O}(|V|^7)\) for the case of general weights.
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References
Björklund, A., Husfeldt, T.: Shortest two disjoint paths in polynomial time. In: Esparza, J., Fraigniaud, P., Husfeldt, T., Koutsoupias, E. (eds.) ICALP 2014. LNCS, vol. 8572, pp. 211–222. Springer, Heidelberg (2014). https://doi.org/10.1007/978-3-662-43948-7_18
Björklund, A., Husfeldt, T.: Counting shortest two disjoint paths in cubic planar graphs with an NC algorithm. ArXiv abs/arXiv:1806.07586 (2018)
Datta, S., Iyer, S., Kulkarni, R., Mukherjee, A.: Shortest \(k\)-disjoint paths via determinants. In: Ganguly, S., Pandya, P. (eds.) 38th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2018). Leibniz International Proceedings in Informatics (LIPIcs), vol. 122, pp. 19:1–19:21. Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik, Dagstuhl (2018). https://doi.org/10.4230/LIPIcs.FSTTCS.2018.19. http://drops.dagstuhl.de/opus/volltexte/2018/9918
Eilam-Tzoreff, T.: The disjoint shortest paths problem. Discrete Appl. Math. 85(2), 113–138 (1998). https://doi.org/10.1016/S0166-218X(97)00121-2. http://www.sciencedirect.com/science/article/pii/S0166218X97001212
Fortune, S., Hopcroft, J., Wyllie, J.: The directed subgraph homeomorphismproblem. Theor. Comput. Sci. 10(2), 111–121 (1980). https://doi.org/10.1016/0304-3975(80)90009-2. http://www.sciencedirect.com/science/article/pii/0304397580900092
Gallai, T.: Maximum-minimum Sätze und verallgemeinerte Faktoren vonGraphen. Acta Math. Acad. Scientiarum Hung. 12(1), 131–173 (1964). https://doi.org/10.1007/BF02066678
Gustedt, J.: The general two-path problem in time \(\cal{O}(m \log n)\). Technical report 394, TU Berlin (1994)
Hirai, H., Namba, H.: Shortest \((a+b)\)-path packing via Hafnian. Algorithmica 80(8), 2478–2491 (2018). https://doi.org/10.1007/s00453-017-0334-0
Lynch, J.F.: The equivalence of theorem proving and the interconnection problem. SIGDA Newsl. 5(3), 31–36 (1975). https://doi.org/10.1145/1061425.1061430
Robertson, N., Seymour, P.D.: Disjoint paths–a survey. SIAM J. Algebraic Discrete Methods 6(2), 300–305 (1985). https://doi.org/10.1137/0606030
Williams, V.V.: Multiplying matrices faster than Coppersmith-Winograd. In: Proceedings of the Forty-Fourth Annual ACM Symposium on Theory of Computing, STOC 2012, pp. 887–898. ACM, New York (2012). https://doi.org/10.1145/2213977.2214056
Acknowledgements
I would like to express gratitude to Maxim Babenko for pointing me to the original article [4] and suggesting to investigate the possibility of optimization, for a lot of helpful discussions and for helping me with the preparation of the paper text.
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Akhmedov, M. (2020). Faster 2-Disjoint-Shortest-Paths Algorithm. In: Fernau, H. (eds) Computer Science – Theory and Applications. CSR 2020. Lecture Notes in Computer Science(), vol 12159. Springer, Cham. https://doi.org/10.1007/978-3-030-50026-9_7
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