Connected facility location via random facility sampling and core detouring

Eisenbrand, Friedrich and Grandoni, Fabrizio and Rothvoß, Thomas and Schäfer, Guido (2010) Connected facility location via random facility sampling and core detouring. Journal of Computer and System Sciences, 76 (8). pp. 709-726. ISSN 0022-0000

1-s2.0-S0022000010000152-main.pdf - Published Version

Download (299kB) | Preview


We present a simple randomized algorithmic framework for connected facility location problems. The basic idea is as follows: We run a black-box approximation algorithm for the unconnected facility location problem, randomly sample the clients, and open the facilities serving sampled clients in the approximate solution. Via a novel analytical tool, which we term core detouring, we show that this approach significantly improves over the previously best known approximation ratios for several NP-hard network design problems. For example, we reduce the approximation ratio for the connected facility location problem from 8.55 to 4.00 and for the single-sink rent-or-buy problem from 3.55 to 2.92. The mentioned results can be derandomized at the expense of a slightly worse approximation ratio. The versatility of our framework is demonstrated by devising improved approximation algorithms also for other related problems.

Actions (login required)

View Item View Item