Skip to main content
Log in

A Randomized O(log2 k)-Competitive Algorithm for Metric Bipartite Matching

  • Published:
Algorithmica Aims and scope Submit manuscript

Abstract

We consider the online metric matching problem in which we are given a metric space, k of whose points are designated as servers. Over time, up to k requests arrive at an arbitrary subset of points in the metric space, and each request must be matched to a server immediately upon arrival, subject to the constraint that at most one request is matched to any particular server. Matching decisions are irrevocable and the goal is to minimize the sum of distances between the requests and their matched servers.

We give an O(log2 k)-competitive randomized algorithm for the online metric matching problem. This improves upon the best known guarantee of O(log3 k) on the competitive factor due to Meyerson, Nanavati and Poplawski (SODA ’06, pp. 954–959, 2006). It is known that for this problem no deterministic algorithm can have a competitive better than 2k−1, and that no randomized algorithm can have a competitive ratio better than lnk.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1

Similar content being viewed by others

Notes

  1. For any weighted undirected graph G=(V,E,w), it is possible to define a corresponding metric (V,d), by defining d(u,v) as the shortest path between u in v in G with edge weights w. It is easy to verify that this is indeed a metric space. A line metric is the metric induced by a line graph (with edge weights 1).

References

  1. Baeza-Yates, R.A., Culberson, J.C., Rawlins, G.J.E.: Searching in the plane. Inf. Comput. 106(2), 234–252 (1991)

    Article  MathSciNet  Google Scholar 

  2. Bartal, Y.: Probabilistic approximation of metric spaces and its algorithmic applications. In: 37th Annual Symposium on Foundations of Computer Science, pp. 184–193 (1996)

    Google Scholar 

  3. Bartal, Y.: On approximating arbitrary metrics by tree metrics. In: Proceedings of the 30th Annual ACM Symposium on Theory of Computing, pp. 161–168 (1998)

    Google Scholar 

  4. Buchbinder, N., Jain, K., Naor, J.: Online primal-dual algorithms for maximizing ad-auctions revenue. In: European Symposium on Algorithms (ESA), pp. 253–264 (2007)

    Google Scholar 

  5. Chung, C., Pruhs, K., Uthaisombut, P.: The online transportation problem: on the exponential boost of one extra server. In: Latin American Theoretical Informatics (LATIN), pp. 228–239 (2008)

    Google Scholar 

  6. Fakcharoenphol, J., Rao, S., Talwar, K.: A tight bound on approximating arbitrary metrics by tree metrics. J. Comput. Syst. Sci. 69(3), 485–497 (2004)

    Article  MATH  MathSciNet  Google Scholar 

  7. Fuchs, B., Hochstättler, W., Kern, W.: Online matching on a line. Theor. Comput. Sci. 332(1–3), 251–264 (2005)

    Article  MATH  Google Scholar 

  8. Goemans, M., Williamson, D.P.: A general approximation technique for constrained forest problems. SIAM J. Comput. 24, 296–317 (1992)

    Article  MathSciNet  Google Scholar 

  9. Kalyanasundaram, B., Pruhs, K.: Online weighted matching. J. Algorithms 14(3), 478–488 (1993)

    Article  MATH  MathSciNet  Google Scholar 

  10. Kalyanasundaram, B., Pruhs, K.: On-line network optimization problems. In: Online Algorithms, pp. 268–280 (1996)

    Google Scholar 

  11. Kalyanasundaram, B., Pruhs, K.: The online transportation problem. SIAM J. Discrete Math. 13(3), 370–383 (2000)

    Article  MathSciNet  Google Scholar 

  12. Kalyanasundaram, B., Pruhs, K.: An optimal deterministic algorithm for online b-matching. Theor. Comput. Sci. 233(1–2), 319–325 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  13. Karp, R.M., Vazirani, U.V., Vazirani, V.V.: An optimal algorithm for on-line bipartite matching. In: STOC, pp. 352–358 (1990)

    Google Scholar 

  14. Khuller, S., Mitchell, S.G., Vazirani, V.V.: On-line algorithms for weighted bipartite matching and stable marriages. Theor. Comput. Sci. 127(2), 255–267 (1994)

    Article  MATH  MathSciNet  Google Scholar 

  15. Koutsoupias, E., Nanavati, A.: The online matching problem on a line. In: Workshop on Approximation and Online Algorithms, pp. 179–191 (2003)

    Google Scholar 

  16. Koutsoupias, E., Papadimitriou, C.H.: On the k-server conjecture. J. ACM 42(5), 971–983 (1995)

    Article  MATH  MathSciNet  Google Scholar 

  17. Manasse, M.S., McGeoch, L.A., Sleator, D.D.: Competitive algorithms for server problems. J. Algorithms 11(2), 208–230 (1990)

    Article  MATH  MathSciNet  Google Scholar 

  18. Mehta, A., Saberi, A., Vazirani, U., Vazirani, V.: Adwords and generalized online matching. J. ACM 54(5) (2007)

  19. Meyerson, A., Nanavati, A., Poplawski, L.: Randomized online algorithms for minimum metric bipartite matching. In: SODA ’06, pp. 954–959 (2006)

    Chapter  Google Scholar 

  20. Plaisted, D.A.: Heuristic matching for graphs satisfying the triangle inequality. J. Algorithms 5(2), 163–179 (1984)

    Article  MATH  MathSciNet  Google Scholar 

  21. Reingold, E.M., Tarjan, R.E.: On a greedy heuristic for complete matching. SIAM J. Comput. 10(4), 676–681 (1981)

    Article  MATH  MathSciNet  Google Scholar 

  22. Schrijver, A.: Combinatorial Optimization: Polyhedra and Efficiency. Algorithms and Combinatorics, vol. 24. Springer, Berlin (2003)

    Google Scholar 

  23. Supowit, K.J., Reingold, E.M., Plaisted, D.A.: The travelling salesman problem and minimum matching in the unit square. SIAM J. Comput. 12(1), 144–156 (1983)

    Article  MATH  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Niv Buchbinder.

Additional information

A preliminary version appeared in the 15th Annual European Symposium on Algorithms (ESA), 2007.

N. Buchbinder was supported by ISF grant 954/11 and BSF grant 2010426. A. Gupta was supported by NSF awards CCF-0964474 and CCF-1016799. J. Naor was supported by ISF grant 954/11 and BSF grant 2010426.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bansal, N., Buchbinder, N., Gupta, A. et al. A Randomized O(log2 k)-Competitive Algorithm for Metric Bipartite Matching. Algorithmica 68, 390–403 (2014). https://doi.org/10.1007/s00453-012-9676-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00453-012-9676-9

Keywords

Navigation