Planar Maximum Box Problem

Given two finite sets of points X+ and X− in ℝd, the maximum box problem asks to find an axis-parallel box B such that B∩X−=∅ and the total number of points from X+ covered is maximized. In this paper we consider the version of the problem for d = 2 (and find the smallest solution box). We present an O(n3 log4n) runtime algorithm, thus improving previously best known solution by almost quadratic factor.