We build on the classical greedy sequential set cover algorithm, in the spirit of the primal-dual schema, to obtain simple parallel approximation algorithms for the set cover problem and its generalizations. Our algorithms use randomization, and our randomized voting lemmas may be of independent interest. Fast parallel approximation algorithms were known before for set cover, though not for the generalizations considered in this paper. Key words. algorithms, set cover, primal-dual, parallel, approximation, voting lemmas PII. S0097539793260763
Sridhar Rajagopalan, Vijay V. Vazirani