eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Leibniz International Proceedings in Informatics
1868-8969
2018-07-04
71:1
71:14
10.4230/LIPIcs.ICALP.2018.71
article
Maximizing Profit with Convex Costs in the Random-order Model
Gupta, Anupam
1
Mehta, Ruta
2
Molinaro, Marco
3
Carnegie Mellon University, Pittsburgh, USA
University of Illinois Urbana-Champaign, Champaign, USA
PUC-Rio, Rio de Janeiro, Brazil
Suppose a set of requests arrives online: each request gives some value v_i if accepted, but requires using some amount of each of d resources. Our cost is a convex function of the vector of total utilization of these d resources. Which requests should be accept to maximize our profit, i.e., the sum of values of the accepted demands, minus the convex cost?
We consider this problem in the random-order a.k.a. secretary model, and show an O(d)-competitive algorithm for the case where the convex cost function is also supermodular. If the set of accepted demands must also be independent in a given matroid, we give an O(d^3 alpha)-competitive algorithm for the supermodular case, and an improved O(d^2 alpha) if the convex cost function is also separable. Here alpha is the competitive ratio of the best algorithm for the submodular secretary problem. These extend and improve previous results known for this problem. Our techniques are simple but use powerful ideas from convex duality, which give clean interpretations of existing work, and allow us to give the extensions and improvements.
https://drops.dagstuhl.de/storage/00lipics/lipics-vol107-icalp2018/LIPIcs.ICALP.2018.71/LIPIcs.ICALP.2018.71.pdf
Online algorithms
secretary problem
random order
convex duality