English

Enumerating Cryptarithms Using Deterministic Finite Automata

Formal Languages and Automata Theory 2018-08-01 v1 Data Structures and Algorithms

Abstract

A cryptarithm is a mathematical puzzle where given an arithmetic equation written with letters rather than numerals, a player must discover an assignment of numerals on letters that makes the equation hold true. In this paper, we propose a method to construct a DFA that accepts cryptarithms that admit (unique) solutions for each base. We implemented the method and constructed a DFA for bases k7k \le 7. Those DFAs can be used as complete catalogues of cryptarithms,whose applications include enumeration of and counting the exact numbers Gk(n)G_k(n) of cryptarithm instances with nn digits that admit base-kk solutions. Moreover, explicit formulas for G2(n)G_2(n) and G3(n)G_3(n) are given.

Keywords

Cite

@article{arxiv.1807.11580,
  title  = {Enumerating Cryptarithms Using Deterministic Finite Automata},
  author = {Yuki Nozaki and Diptarama Hendrian and Ryo Yoshinaka and Takashi Horiyama and Ayumi Shinohara},
  journal= {arXiv preprint arXiv:1807.11580},
  year   = {2018}
}