On List Colouring and List Homomorphism of Permutation and Interval Graphs
Jessica A. Enright, Lorna K. Stewart, Gábor Tardos · arXiv (Cornell University) · 2012
List colouring is an NP-complete decision problem even if the total number of colours is three. It is hard even on planar bipartite graphs. We give a polynomial-time algorithm for solving list colouring of permutation graphs with a bounded total number of colours. More generally we give a polynomial-time algorithm that solves the list-homomorphism problem to any fixed target graph for a large class of input graphs including all permutation and interval graphs.