A k-L(2, 1)-labeling of a graph is a function from its vertex set into the set {0, . . . , k}, such that the labels assigned to adjacent vertices differ by at least 2, and labels assigned to vertices of distance 2 are different. It is known that finding the smallest k admitting the existence of a k-L(2, 1)labeling of any given graph is NP-Complete. In this paper we present an algorithm for this...