English

Finding a Small Number of Colourful Components

Data Structures and Algorithms 2018-08-13 v1

Abstract

A partition (V1,,Vk)(V_1,\ldots,V_k) of the vertex set of a graph GG with a (not necessarily proper) colouring cc is colourful if no two vertices in any ViV_i have the same colour and every set ViV_i induces a connected graph. The COLOURFUL PARTITION problem is to decide whether a coloured graph (G,c)(G,c) has a colourful partition of size at most kk. This problem is closely related to the COLOURFUL COMPONENTS problem, which is to decide whether a graph can be modified into a graph whose connected components form a colourful partition by deleting at most pp edges. Nevertheless we show that COLOURFUL PARTITION and COLOURFUL COMPONENTS may have different complexities for restricted instances. We tighten known NP-hardness results for both problems and in addition we prove new hardness and tractability results for COLOURFUL PARTITION. Using these results we complete our paper with a thorough parameterized study of COLOURFUL PARTITION.

Keywords

Cite

@article{arxiv.1808.03561,
  title  = {Finding a Small Number of Colourful Components},
  author = {Laurent Bulteau and Konrad K. Dabrowski and Guillaume Fertin and Matthew Johnson and Daniel Paulusma and Stephane Vialette},
  journal= {arXiv preprint arXiv:1808.03561},
  year   = {2018}
}
R2 v1 2026-06-23T03:30:01.802Z