Approximation Schemes for the Betweenness Problem in Tournaments and Related Ranking Problems (Revised Version)
نویسندگان
چکیده
We settle the approximability of the Minimum Betweenness problem in tournaments by designing a polynomial time approximation scheme (PTAS). No constant factor approximation was previously known. We also introduce a more general class of so-called fragile ranking problems and construct PTASs for them. The results depend on a new technique of dealing with fragile ranking constraints and could be of independent interest. Dept. of Computer Science, University of Bonn. Parts of this work done while visiting Microsoft Research. Email: [email protected] IBM T. J. Watson Research Center. Parts of this work done while a student at Brown University and while visiting University of Bonn. Email: [email protected]
منابع مشابه
Approximation Schemes for the Betweenness Problem in Tournaments and Related Ranking Problems
We design the first polynomial time approximation schemes (PTASs) for the Minimum Betweenness problem in tournaments and some related higher arity ranking problems. This settles the approximation status of the Betweenness problem in tournaments along with other ranking problems which were open for some time now. The results depend on a new technique of dealing with fragile ranking constraints a...
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