On the Complexity of Ordered Colorings

We introduce two variants of proper colorings with imposed partial ordering on the set of colors. One variant shows very close connections to some fundamental problems in graph theory, e.g., directed graph homomorphism and list colorings. We study the border between tractability and intractability for both variants. Key words. graph coloring, ordered coloring, directed graph homomorphism, complexity, NPcompleteness, polynomial algorithm AMS subject classifications. 05C15, 68Q25, 05C85 DOI. 10.1137/060676222

• Type: Journal
• Year: 2008
• Where: SIAMDM
• Authors: Arvind Gupta, Jan van den Heuvel, Ján Manuch, Ladislav Stacho, Xiaohong Zhao
• Keywords: Graph Homomorphism, Graph Theory, Proper Colorings, SIAMDM 2008