Random order contention resolution schemes

Marek Adamczyk, Michał Włodarczyk

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

22 Scopus citations


Contention resolution schemes have proven to be an incredibly powerful concept which allows tackling a broad class of problems. The framework has been initially designed to handle submodular optimization under various types of constraints, that is, intersections of exchange systems (including matroids), knapsacks, and unsplittable flows on trees. Later on, it turned out that this framework perfectly extends to optimization under uncertainty, like stochastic probing and online selection problems, which further can be applied to mechanism design. We add to this line of work by showing how to create contention resolution schemes for intersection of matroids and knapsacks when we work in the random order setting. More precisely, we do know the whole universe of elements in advance, but they appear in an order given by a random permutation. Upon arrival we need to irrevocably decide whether to take an element or not. We bring a novel technique for analyzing procedures in the random order setting that is based on the martingale theory. This unified approach makes it easier to combine constraints, and we do not need to rely on the monotonicity of contention resolution schemes, as it was the case before. Our paper fills the gaps, extends, and creates connections between many previous results and techniques. The main application of our framework is a k + 4 + ϵ approximation ratio for the Bayesian multi-parameter unit-demand mechanism design under the constraint of k matroids intersection, which improves upon the previous bounds of 4k - 2 and ϵ(k + 1). Other results include improved approximation ratios for stochastic k-set packing and submodular stochastic probing over arbitrary non-negative submodular objective function, whereas previous results required the objective to be monotone.

Original languageEnglish
Title of host publicationProceedings - 59th Annual IEEE Symposium on Foundations of Computer Science, FOCS 2018
EditorsMikkel Thorup
PublisherInstitute of Electrical and Electronics Engineers
Number of pages12
ISBN (Electronic)9781538642306
StatePublished - 30 Nov 2018
Externally publishedYes
Event59th Annual IEEE Symposium on Foundations of Computer Science, FOCS 2018 - Paris, France
Duration: 7 Oct 20189 Oct 2018

Publication series

NameProceedings - Annual IEEE Symposium on Foundations of Computer Science, FOCS
ISSN (Print)0272-5428


Conference59th Annual IEEE Symposium on Foundations of Computer Science, FOCS 2018

ASJC Scopus subject areas

  • Computer Science (all)


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