Approximation Schemes for the Betweenness Problem in Tournaments and Related Ranking Problems
نویسندگان
چکیده
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 and could be of independent interest.
منابع مشابه
Approximation Schemes for the Betweenness Problem in Tournaments and Related Ranking Problems (Revised Version)
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 ...
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