A Unified Approach to Approximating Partial Covering Problems

  • Authors:
  • Jochen Könemann;Ojas Parekh;Danny Segev

  • Affiliations:
  • University of Waterloo, Department of Combinatorics and Optimization, N2L 3G1, Waterloo, Ontario, Canada;Emory University, Department of Mathematics and Computer Science, 30322, Atlanta, GA, USA;MIT, Sloan School of Management, 02139, Cambridge, MA, USA

  • Venue:
  • Algorithmica
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

An instance of the generalized partial cover problem consists of a ground set U and a family of subsets ${\mathcal{S}}\subseteq 2^{U}$. Each element e∈U is associated with a profit p(e), whereas each subset $S\in \mathcal{S}$ has a cost c(S). The objective is to find a minimum cost subcollection $\mathcal{S}'\subseteq \mathcal{S}$ such that the combined profit of the elements covered by $\mathcal{S}'$ is at least P, a specified profit bound. In the prize-collecting version of this problem, there is no strict requirement to cover any element; however, if the subsets we pick leave an element e∈U uncovered, we incur a penalty of π(e). The goal is to identify a subcollection $\mathcal{S}'\subseteq \mathcal{S}$ that minimizes the cost of $\mathcal{S}'$ plus the penalties of uncovered elements. Although problem-specific connections between the partial cover and the prize-collecting variants of a given covering problem have been explored and exploited, a more general connection remained open. The main contribution of this paper is to establish a formal relationship between these two variants. As a result, we present a unified framework for approximating problems that can be formulated or interpreted as special cases of generalized partial cover. We demonstrate the applicability of our method on a diverse collection of covering problems, for some of which we obtain the first non-trivial approximability results.