MathDB
Putnam 2006 B3

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December 4, 2006
Putnamrotationinductionfloor functionceiling functioncollege contests

Problem Statement

Let SS be a finite set of points in the plane. A linear partition of SS is an unordered pair {A,B}\{A,B\} of subsets of SS such that AB=S, AB=,A\cup B=S,\ A\cap B=\emptyset, and AA and BB lie on opposite sides of some straight line disjoint from SS (AA or BB may be empty). Let LSL_{S} be the number of linear partitions of S.S. For each positive integer n,n, find the maximum of LSL_{S} over all sets SS of nn points.