Randomized Rounding for Routing and Covering Problems: Experiments and Improvements

We investigate how the recently developed different approaches to generate randomized roundings satisfying disjoint cardinality constraints behave when used in two classical algorithmic problems, namely low-congestion routing in networks and max-coverage problems in hypergraphs. Based on our experiments, we also propose and investigate the following new ideas. For the lowcongestion routing problems, we suggest to solve a second LP, which yields the same congestion, but aims at producing a solution that is easier to round. For the max-coverage instances, observing that the greedy heuristic also performs very good, we develop hybrid approaches, in the form of a strengthened method of derandomized rounding, and a simple greedy/rounding hybrid using greedy and LP-based rounding elements. Experiments show that these ideas significantly reduce the rounding errors. For an important special case of max-coverage, namely unit disk max-domination, we also develop a PTAS. However, experiments sho...

• Type: Conference
• Year: 2010
• Where: WEA
• Authors: Benjamin Doerr, Marvin Künnemann, Magnus Wahlström
• Keywords: Algorithms, Classical Algorithmic Problems, Disjoint Cardinality Constraints, Lowcongestion Routing Problems, WEA 2010