English

Universal Cycles of Complementary Classes

Combinatorics 2013-03-15 v1

Abstract

Universal Cycles, or U-cycles, as originally defined by de Bruijn, are an efficient method to exhibit a large class of combinatorial objects in a compressed fashion, and with no repeats. de Bruijn's theorem states that U-cycles for nn letter words on a kk letter alphabet exist for all kk and nn. Much has already been proved about Universal Cycles for a variety of other objects. This work is intended to augment the current research in the area by exhibiting U-cycles for {\it complementary classes}. Results will be presented that exhibit the existence of U-cycles for class-alternating words such as alternating vowel-consonant (VCVC) words; words with at least one repeated letter (non-injective functions); words with at least one letter of the alphabet missing (functions that are not onto); words that represent illegal tournament rankings; and words that do not constitute "strong" legal computer passwords. As with previous papers pertaining to U-cycles, connectedness proves to be a nontrivial step.

Keywords

Cite

@article{arxiv.1303.3323,
  title  = {Universal Cycles of Complementary Classes},
  author = {Michelle Champlin and Anant Godbole and Beverly Tomlinson},
  journal= {arXiv preprint arXiv:1303.3323},
  year   = {2013}
}

Comments

6 pages

R2 v1 2026-06-21T23:41:45.600Z