Computing Kemeny Rankings, Parameterized by the Average KT-Distance
نویسندگان
چکیده
The computation of Kemeny rankings is central to many applications in the context of rank aggregation. Unfortunately, the problem is NP-hard. Extending our previous work [AAIM 2008], we show that the Kemeny score of an election can be computed efficiently whenever the average pairwise distance between two input votes is not too large. In other words, Kemeny Score is fixed-parameter tractable with respect to the parameter “average pairwise Kendall-Tau distance da”. We describe a fixedparameter algorithm with running time O(16a · poly).
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