Abstract
Facility location is a prominent optimization problem that has inspired a large quantity of both theoretical and practical studies in combinatorial optimization. Although the problem has been investigated under various settings reflecting typical structures within the optimization problems of practical interest, little is known on how the problem behaves in conjunction with parity constraints. This shortfall of understanding was rather discouraging when we consider the central role of parity in the field of combinatorics. In this paper, we present the first constant-factor approximation algorithm for the facility location problem with parity constraints. We are given as the input a metric on a set of facilities and clients, the opening cost of each facility, and the parity requirement–\(\textsf{odd}\), \(\textsf{even}\), or \(\textsf{unconstrained}\)–of every facility in this problem. The objective is to open a subset of facilities and assign every client to an open facility so as to minimize the sum of the total opening costs and the assignment distances, but subject to the condition that the number of clients assigned to each open facility must have the same parity as its requirement. Although the unconstrained facility location problem as a relaxation for this parity-constrained generalization has unbounded gap, we demonstrate that it yields a structured solution whose parity violation can be corrected at small cost. This correction is prescribed by a T-join on an auxiliary graph constructed by the algorithm. This auxiliary graph does not satisfy the triangle inequality, but we show that a carefully chosen set of shortcutting operations leads to a cheap and sparse T-join. Finally, we bound the correction cost by exhibiting a combinatorial multi-step construction of an upper bound. We also consider the parity-constrained k-center problem, the bottleneck optimization variant of parity-constrained facility location. We present the first constant-factor approximation algorithm also for this problem.
Similar content being viewed by others
Notes
In Sect. 4.5, we show that a more careful analysis yields the approximation ratio of 5.813.
Consider an instance with two pairs of an even-constrained facility and a client, where the distance within each pair is zero and one across. Both opening costs are zeroes.
We obtain a 6-approximation algorithm that runs in \(O(|V|^2\log |V|)\) time; whilst this approximation ratio is obtained under the standard setting where there is no distinction between facilities and clients, we can easily extend the analysis to obtain an O(1)-approximation algorithm even with the distinction.
Assignment costs are sometimes defined only between facilities and clients. In this “bipartite” case, the domain of c will be defined as \(F\times D\) instead. These two definitions, however, are equivalent, since we can deduce inter-facility (and inter-client) distances by computing the metric closure of the given “bipartite” assignment cost.
We remark that a more careful analysis yields a tighter bound of \(2 c(\sigma _\mathcal {I}) + 2 c(\sigma _\mathcal {O}) + f(S_\mathcal {O}) \), although we present the current proof in favor of simplicity.
References
Adamaszek, A., Antoniadis, A., Kumar, A., Mömke, T.: Approximating airports and railways. In: Symposium on Theoretical Aspects of Computer Science (STACS), vol. 6, pp 5:1–5:13 2018
Ahamad, M., Ammar, M.H.: Performance characterization of quorum-consensus algorithms for replicated data. IEEE Trans. Softw. Eng. 15(4), 492–496 (1989)
Ahmadian, S., Friggstad, Z., Swamy, C.: Local-search based approximation algorithms for mobile facility location problems. In: ACM-SIAM Symposium on Discrete Algorithms (SODA), pp 1607–1621 2013
An, H.C., Bhaskara, A., Chekuri, C., Gupta, S., Madan, V., Svensson, O.: Centrality of trees for capacitated \(k\)-center. Math. Program. 154(1), 29–53 (2015)
An, H.C., Singh, M., Svensson, O.: LP-based algorithms for capacitated facility location. SIAM J. Comput. 46(1), 272–306 (2017)
Balinski, M.L.: On finding integer solutions to linear programs. Tech. Rep. Mathematica Princeton, NJ (1964)
Bansal, M., Garg, N., Gupta, N.: A 5-approximation for capacitated facility location. In: European Symposium on Algorithms (ESA), pp 133–144 2012
Benczúr, A.A., Fülöp, O.: Fast algorithms for even/odd minimum cuts and generalizations. In: European Symposium on Algorithms (ESA), pp 88–99 2000
Byrka, J.: An optimal bifactor approximation algorithm for the metric uncapacitated facility location problem. In: Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques, pp 29–43 2007
Byrka, J., Ghodsi, M., Srinivasan, A.: LP-rounding algorithms for facility-location problems. arXiv preprint arXiv:1007.3611 2010
Chan, T.H.H., Guerqin, A., Sozio, M.: Fully dynamic \(k\)-center clustering. In: World Wide Web Conference (WWW), pp 579–587 2018
Cheriyan, J., Friggstad, Z., Gao, Z.: Approximating minimum-cost connected \(T\)-joins. Algorithmica 72(1), 126–147 (2015)
Cygan, M., Hajiaghayi, M., Khuller, S.: LP rounding for \(k\)-centers with non-uniform hard capacities. In: IEEE Symposium on Foundations of Computer Science (FOCS), pp 273–282 2012
Cygan, M., Czumaj, A., Mucha, M., Sankowski, P.: Online facility location with deletions. In: European Symposium on Algorithms (ESA), pp 21:1–21:15 2018
Demaine, E.D., Fomin, F.V., Hajiaghayi, M., Thilikos, D.M.: Fixed-parameter algorithms for \((k, r)\)-center in planar graphs and map graphs. ACM Trans. Algorithm. 1(1), 33–47 (2005)
Edmonds, J., Johnson, E.: Matching, Euler tours and the Chinese postman. Math. Program. 5, 88–124 (1973)
Eisenstat, D., Klein, P.N., Mathieu, C.: Approximating k-center in planar graphs. In: ACM-SIAM Symposium on Discrete Algorithms (SODA), pp 617–627 2014a
Eisenstat, D., Mathieu, C., Schabanel, N.: Facility location in evolving metrics. In: International Colloquium on Automata, Languages, and Programming (ICALP), pp 459–470 2014b
Ene, A., Har-Peled, S., Raichel, B.: Fast clustering with lower bounds: No customer too far, no shop too small. arXiv preprint arXiv:1304.7318 2013
Everett, H., de Figueiredo, C.M., Linhares-Sales, C., Maffray, F., Porto, O., Reed, B.A.: Path parity and perfection. Discret. Math. 165, 233–252 (1997)
Goranci, G., Henzinger, M., Leniowski, D.: A tree structure for dynamic facility location. In: European Symposium on Algorithms (ESA), pp 39:1–39:13 2018
Grötschel, M., Pulleyblank, W.R.: Weakly bipartite graphs and the max-cut problem. Oper. Res. Lett. 1(1), 23–27 (1981)
Grötschel, M., Lovász, L., Schrijver, A.: The ellipsoid method and its consequences in combinatorial optimization. Combinatorica 1(2), 169–197 (1981)
Grötschel, M., Lovász, L., Schrijver, A.: Corrigendum to our paper “the ellipsoid method and its consequences in combinatorial optimization’’. Combinatorica 4(4), 291–295 (1984)
Hochbaum, D.S., Shmoys, D.B.: A best possible heuristic for the \(k\)-center problem. Math. Oper. Res. 10(2), 180–184 (1985)
Jain, K., Vazirani, V.V.: Approximation algorithms for metric facility location and \(k\)-median problems using the primal-dual schema and Lagrangian relaxation. J. ACM 48(2), 274–296 (2001)
Jain, K., Mahdian, M., Saberi, A.: A new greedy approach for facility location problems. In: ACM Symposium on Theory of Computing (STOC), pp 731–740 2002
Kakimura, N., Kawarabayashi, K., Kobayashi, Y. Erdős-Pósa property and its algorithmic applications — parity constraints, subset feedback set, and subset packing. In: ACM-SIAM Symposium on Discrete Algorithms (SODA), pp 1726–1736 2012
Kaminski, M., Nishimura, N.: Finding an induced path of given parity in planar graphs in polynomial time. In: ACM-SIAM Symposium on Discrete Algorithms (SODA), pp 656–670 2012
Khuller, S., Sussmann, Y.: The capacitated \(k\)-center problem. SIAM J. Discret. Math. 13(3), 403–418 (2000)
Kim, K., Shin, Y., An, H.C.: Constant-Factor Approximation Algorithms for the Parity-Constrained Facility Location Problem. In: International Symposium on Algorithms and Computation (ISAAC), Leibniz International Proceedings in Informatics (LIPIcs), vol. 181, pp 21:1–21:17 2020
Korupolu, M.R., Plaxton, C., Rajaraman, R.: Analysis of a local search heuristic for facility location problems. J. Algorithm. 37(1), 146–188 (2000)
Kuehn, A.A., Hamburger, M.J.: A heuristic program for locating warehouses. Manage. Sci. 9(4), 643–666 (1963)
Lammersen, C., Sohler, C.: Facility location in dynamic geometric data streams. In: European Symposium on Algorithms (ESA), pp 660–671 2008
Li, S.: A 1.488 approximation algorithm for the uncapacitated facility location problem. In: International Colloquium on Automata, Languages, and Programming (ICALP), pp 77–88 2011
Li, S.: On facility location with general lower bounds. In: ACM-SIAM Symposium on Discrete Algorithms (SODA), pp 2279–2290 2019
Manne, A.S.: Plant location under economies-of-scale–decentralization and computation. Manage. Sci. 11(2), 213–235 (1964)
Marx, D., Pilipczuk, M.: Optimal parameterized algorithms for planar facility location problems using Voronoi diagrams. In: European Symposium on Algorithms (ESA), pp 865–877 2015
Maßberg, J., Vygen, J.: Approximation algorithms for a facility location problem with service capacities. ACM Trans. Algorithm. 4(4), 50:1-50:15 (2008)
Matuschke, J., Bley, A., Müller, B.: Approximation algorithms for facility location with capacitated and length-bounded tree connections. In: European Symposium on Algorithms (ESA), pp 707–718 2013
Padberg, M.W., Rao, M.R.: Odd minimum cut-sets and \(b\)-matchings. Math. Oper. Res. 7(1), 67–80 (1982)
Pál, M., Tardos, É., Wexler, T.: Facility location with nonuniform hard capacities. In: IEEE Symposium on Foundations of Computer Science (FOCS), pp 329–338 2001
Schrijver, A.: Combinatorial optimization: polyhedra and efficiency. Springer, Berlin (2003)
Schrijver, A., Seymour, P.: Packing odd paths. J. Comb. Theory 62, 280–288 (1994)
Sebő, A.: Eight-fifth approximation for the path TSP. In: Integer Programming and Combinatorial Optimization (IPCO), pp 362–374 2013
Shmoys, D.B., Tardos, É., Aardal, K.: Approximation algorithms for facility location problems. In: ACM Symposium on Theory of Computing (STOC), pp 265–274 1997
Stollsteimer, J.F.: A working model for plant numbers and locations. J. Farm Econ. 45(3), 631–645 (1963)
The Apache Software Foundation: Apache ZooKeeper. http://zookeeper.apache.org/ 2020
Acknowledgements
We thank the anonymous referees of this paper and its conference version for their helpful comments.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This paper extends its preliminary version [31] that was presented at ISAAC 2020. Sections 5 and 4.5 were newly added in particular.
Part of this research was conducted while K. Kim was at Yonsei University. Part of this research was conducted while H.-C. An was visiting Cornell University. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2019R1C1C1008934). This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2016R1C1B1012910). This research was supported by the Yonsei University Research Fund of 2018-22-0093. This work was partly supported by Institute of Information & communications Technology Planning & Evaluation (IITP) grant funded by the Korea government (MSIT) (No.2021-0-02068, Artificial Intelligence Innovation Hub). This research was supported by the Yonsei Signature Research Cluster Program of 2022 (2022-22-0002).
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Kim, K., Shin, Y. & An, HC. Constant-Factor Approximation Algorithms for Parity-Constrained Facility Location and k-Center. Algorithmica 85, 1883–1911 (2023). https://doi.org/10.1007/s00453-022-01060-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00453-022-01060-5