English

Algorithmic Applications of Tyshkevich's Graph Decomposition: A Primer and a Toolkit

Combinatorics 2026-01-06 v1 Discrete Mathematics

Abstract

A graph that is completely determined by its degree sequence is called a unigraph. In 2000, Regina Tyshkevich published one of the most important papers on unigraphs. There are two parts to the paper: a decomposition theorem that describes how every graph can be broken into a sequence of basic graphs and a complete classification of all basic unigraphs. Together, they reveal how every unigraph is constructed. We provide an informal overview of Tyshkevich's results and show how they enable the computation of various graph parameters of unigraphs in linear time. We also created a toolkit (https://chelseal11.github.io/tyshkevich_decomposition_toolkit/) that implements the algorithms described in this write-up.

Keywords

Cite

@article{arxiv.2601.00957,
  title  = {Algorithmic Applications of Tyshkevich's Graph Decomposition: A Primer and a Toolkit},
  author = {Christine T. Cheng and Chelsea Ann Lambert},
  journal= {arXiv preprint arXiv:2601.00957},
  year   = {2026}
}

Comments

20 pages with a 5-page appendix containing pseudocode