# On L(2,1)-labelings of oriented graphs

## TL;DR

This paper extends the concept of L(2,1)-labelings to oriented graphs, providing bounds and exploring variants to deepen understanding of labeling constraints in directed graph structures.

## Contribution

It introduces new bounds for the L(2,1)-labeling number in oriented graphs and explores variants of the labeling problem.

## Key findings

- Extended bounds for L(2,1)-labeling in oriented graphs
- Analyzed variants of the labeling problem
- Connected results to maximum degree of graphs

## Abstract

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.