Abstract
In this paper, we provide efficient algorithms for solving the weighted center problems in a cactus graph. In particular, an O(n logn) time algorithm is proposed that finds the weighted 1-center in a cactus graph, where n is the number of vertices in the graph. For the weighted 2-center problem, an O(n log3 n) time algorithm is devised for its continuous version and showed that its discrete version is solvable in O(n log2 n) time. No such algorithm was previously known. The obnoxious center problem in a cactus graph can now be solved in O(n log3 n). This improves the previous result of O(cn) where c is the number of distinct vertex weights used in the graph [8]. In the worst case c is O(n).
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Burkard, R.E., Krarup, J.: A linear algorithm for the pos/neg-weighted 1-median problem on cactus. Comput. 60, 498–509 (1998)
Hakimi, S.L.: Optimum location of switching centers and the absolute centers and medians of a graph. Oper. Res. 12, 450–459 (1964)
Kariv, O., Hakimi, S.L.: An algorithmic approach to network location problems, Part I. The p-centers. SIAM J. Appl. Math. 37, 513–538 (1979)
Lan, Y.-F., Wang, Y.-L., Suzuki, H.: A linear-time algorithm for solving the center problem on weighted cactus graphs. Inform. Process. Lett. 71, 205–212 (1999)
Megiddo, N.: Linear-time algorithms for linear programming in R 3 and related problems. SIAM J. Comput. 12(4), 759–776 (1983)
Megiddo, N., Tamir, A.: New results on the complexity of p-center problems. SIAM J. Comput. 12(4), 751–758 (1983)
Tamir, A.: Improved complexity bounds for center location problems on networks by using dynamic data structures. SIAM J. Disc. Math. 1(3), 377–396 (1988)
Zmazek, B., Žerovnik, J.: The obnoxious center problem on weighted cactus graphs. Disc. Appl. Math. 136, 377–386 (2004)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2005 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Ben-Moshe, B., Bhattacharya, B., Shi, Q. (2005). Efficient Algorithms for the Weighted 2-Center Problem in a Cactus Graph. In: Deng, X., Du, DZ. (eds) Algorithms and Computation. ISAAC 2005. Lecture Notes in Computer Science, vol 3827. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11602613_70
Download citation
DOI: https://doi.org/10.1007/11602613_70
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-30935-2
Online ISBN: 978-3-540-32426-3
eBook Packages: Computer ScienceComputer Science (R0)