Partially ordered secretaries

Ragnar Freij (Chalmers University of Technology and University of Gothenburg)
Johan Wästlund (Chalmers University of Technology and University of Gothenburg)

Abstract


The elements of a finite nonempty partially ordered set are exposed at independent uniform times in $[0,1]$ to a selector who, at any given time, can see the structure of the induced partial order on the exposed elements. The selector's task is to choose online a maximal element. This generalizes the classical linear order secretary problem, for which it is known that the selector can succeed with probability $1/e$ and that this is best possible. We describe a strategy for the general problem that achieves success probability at least $1/e$ for an arbitrary partial order.

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Pages: 504-507

Publication Date: October 26, 2010

DOI: 10.1214/ECP.v15-1579

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