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arXiv 1807.11580cs.FLcs.DS
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用确定性有限自动机实现密码计数

Enumerating Cryptarithms Using Deterministic Finite Automata

Yuki Nozaki, Diptarama Hendrian, Ryo Yoshinaka, Takashi Horiyama, Ayumi Shinohara

摘要:

密码是一种数学难题,其中给出了一个用字母而不是数字写的算术方程,玩家必须发现字母上的数字分配,使方程成立。在本文中,我们提出了一种方法来构建一个DFA,接受密码承认(唯一)的解决方案,为每个基地。我们实现了该方法并构造了基$k \le 7$的DFA。这些DFA可以用作密码算法的完整目录,其应用包括枚举和计数具有允许基$k$解的$n$数字的密码算法实例的确切数目$G_k(n)$。并给出了$G_2(n)$和$G_3(n)$的显式表达式。

英文摘要:

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 $k \le 7$. Those DFAs can be used as complete catalogues of cryptarithms,whose applications include enumeration of and counting the exact numbers $G_k(n)$ of cryptarithm instances with $n$ digits that admit base-$k$ solutions. Moreover, explicit formulas for $G_2(n)$ and $G_3(n)$ are given.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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