From Discrepancy to Majority

  • David EppsteinEmail author
  • Daniel S. Hirschberg
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9644)


We show how to select an item with the majority color from n two-colored items, given access to the items only through an oracle that returns the discrepancy of subsets of k items. We use \(n/\lfloor \tfrac{k}{2}\rfloor +O(k)\) queries, improving a previous method by De Marco and Kranakis that used \(n-k+k^2/2\) queries. We also prove a lower bound of \({n/(k-1)-O(n^{1/3})}\) on the number of queries needed, improving a lower bound of \(\lfloor n/k\rfloor \) by De Marco and Kranakis.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Department of Computer ScienceUniversity of CaliforniaIrvineUSA

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