English

The majority game with an arbitrary majority

Combinatorics 2014-02-25 v1

Abstract

The kk-majority game is played with nn numbered balls, each coloured with one of two colours. It is given that there are at least kk balls of the majority colour, where kk is a fixed integer greater than n/2n/2. On each turn the player selects two balls to compare, and it is revealed whether they are of the same colour; the player's aim is to determine a ball of the majority colour. It has been correctly stated by Aigner that the minimum number of comparisons necessary to guarantee success is 2(nk)B(nk)2(n-k) - B(n-k), where B(m)B(m) is the weight of the binary expansion of mm. However his proof contains an error. We give an alternative proof of this result, which generalizes an argument of Saks and Werman.

Keywords

Cite

@article{arxiv.1402.5913,
  title  = {The majority game with an arbitrary majority},
  author = {John R. Britnell and Mark Wildon},
  journal= {arXiv preprint arXiv:1402.5913},
  year   = {2014}
}

Comments

8 pages

R2 v1 2026-06-22T03:14:39.177Z