Precoloring extension on unit interval graphs

In the precoloring extension problem we are given a graph with some of the vertices having a preassigned color and it has to be decided whether this coloring can be extended to a proper k-coloring of the graph. Answering an open question of Hujter and Tuza [6], we show that the precoloring extension problem is NP-complete on unit interval graphs.

• Type: Journal
• Year: 2006
• Where: DAM
• Authors: Dániel Marx
• Keywords: DAM 2006, Extension Problem, Preassigned Color, Proper K-coloring