English

The planar edge-coloring theorem of Vizing in $O(n\log n)$ time

Data Structures and Algorithms 2026-05-06 v2

Abstract

In 1965, Vizing [Diskret. Analiz, 1965] showed that every planar graph of maximum degree Δ8\Delta\ge 8 can be edge-colored using Δ\Delta colors. The direct implementation of the Vizing's proof gives an algorithm that finds the coloring in O(n2)O(n^2) time for an nn-vertex input graph. Chrobak and Nishizeki [J. Algorithms, 1990] have shown a more careful algorithm, which improves the time to O(nlogn)O(n\log n) time, though only for Δ9\Delta\ge 9. In this paper, we extend their ideas to get an algorithm also for the missing case Δ=8\Delta=8. To this end, we modify the original recoloring procedure of Vizing. This generalizes to bounded genus graphs.

Keywords

Cite

@article{arxiv.2507.04516,
  title  = {The planar edge-coloring theorem of Vizing in $O(n\log n)$ time},
  author = {Patryk Jędrzejczak and Łukasz Kowalik},
  journal= {arXiv preprint arXiv:2507.04516},
  year   = {2026}
}

Comments

To appear in Proc. WG 2026