An improved approximation algorithm for the covering 0 – 1 integer program

We present an improved approximation algorithm for the covering 0–1 integer program (CIP), a well-known problem as a natural generalization of the set cover problem. Our algorithm uses a primal–dual algorithm for CIP by Fujito (2004) as a subroutine and achieves an approximation ratio of ( f − f−1 m ) when m ≥ 2, where m is the number of the constraints and f is the maximum number of non-zero entries in the constraints. In addition, when m = 1 our algorithm can be regarded as a PTAS. These results improve the previously known approximation ratio f . keywords: Approximation algorithms, Covering integer program, Primal-dual method