An analysis of approximations for maximizing submodular set functions—II

Abstract

LetN be a finite set andz be a real-valued function defined on the set of subsets ofN that satisfies z (S)+ z (T)= z (S? T)+ z (S? T) for allS, T inN. Such a function is called submodular. We consider the problem max S? N {a (S):| S|= K, z (S) submodular}.