Abstract
Given an undirected graph G=(V,E) and three specified terminal nodes t
1,t
2,t
3, a 3-cut is a subset A of E such that no two terminals are in the same component of G\A. If a non-negative edge weight c
e
is specified for each e∈E, the optimal 3-cut problem is to find a 3-cut of minimum total weight. This problem is -hard, and in fact, is max-
-hard. An approximation algorithm having performance guarantee
has recently been given by Călinescu, Karloff, and Rabani. It is based on a certain linear-programming relaxation, for which it is shown that the optimal 3-cut has weight at most
times the optimal LP value. It is proved here that
can be improved to
, and that this is best possible. As a consequence, we obtain an approximation algorithm for the optimal 3-cut problem having performance guarantee
. In addition, we show that
is best possible for this algorithm.
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References
Calinescu, G., Karloff, H., Rabani, Y.: An improved approximation algorithm for MULTIWAY CUT. Proc. ACM Symp. Theory Comput. 1998, pp. 48–52
Calinescu, G., Karloff, H., Rabani, Y.: An improved approximation algorithm for MULTIWAY CUT. J. Comput. Syst. Sci. 60, 564–574 (2000)
Cheung, K.K.H., Cunningham, W.H., Tang, L.: Optimal 3-terminal cuts and linear programming. Technical Report CORR 2002-24, Dept. of Combinatorics and Optimization, University of Waterloo, Waterloo, Ontario, August 2002
Chopra, S., Rao, M.R.: On the multiway cut polyhedron. Networks 21, 51–89 (1991)
Cunningham, W.H.: The optimal multiterminal cut problem. In: C. Monma, F. Hwang (eds.), Reliability of Computer and Communications Networks, American Math. Soc., 1991, pp. 105–120
Cunningham, W.H., Tang, L.: Optimal 3-terminal cuts and linear programming, Integer programming and combinatorial optimization. Lecture Notes in Comput. Sci. 1610, 114–125 (1999)
Dahlhaus, E., Johnson, D., Papadimitriou, C., Seymour, P., Yannakakis, M.: The Complexity of multiway cuts, extended abstract, 1983
Dahlhaus, E., Johnson, D., Papadimitriou, C., Seymour, P., Yannakakis, M.: The Complexity of multiterminal cuts. SIAM J. Comput. 23, 864–894 (1994)
Freund, A., Karloff, H.: A lower bound of
on the integrality ratio of the Calinescu-Karloff-Rabani relaxation for multiway cut. Inf. Process. Lett. 75, 43–50 (2000)
Karger, D., Klein, P., Stein, C., Thorup, M., Young, N.: Rounding algorithms for a geometric embedding of minimum multiway cut. Proc. ACM Symp. Theory Comput. 1999, pp. 668–678
Karger, D., Klein, P., Stein, C., Thorup, M., Young, N.: Rounding algorithms for a geometric embedding of minimum multiway cut. Math. Oper. Res. 29, 436–461 (2004)
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Research of this author was supported by NSERC PGSB.
Research supported by a grant from NSERC of Canada.
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Cheung, K., Cunningham, W. & Tang, L. Optimal 3-terminal cuts and linear programming. Math. Program. 106, 1–23 (2006). https://doi.org/10.1007/s10107-005-0668-2
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DOI: https://doi.org/10.1007/s10107-005-0668-2