On L(2,1) -labelings of oriented graphs
Lucas Colucci, Ervin Győri · Discussiones Mathematicae Graph Theory · 2019
We extend a result of Griggs and Yeh about the maximum possible value of the L(2,1)-labeling number of a graph in terms of its maximum degree to oriented graphs. We consider the problem both in the usual definition of the oriented L(2,1)-labeling number and in some variants we introduce.