Solving Cryptarithmetic Puzzles by Logic Programming

Abstract

As a personal interest of study, I tried a logic programming approach towards the problem solving of cryptarithmetic puzzles that are commonly discussed as a subcategory of constraint satisfaction problems in the literature of artificial intelligence. While there are possibly several methods capable of solving constraint satisfaction problems, I took into consideration the efficiency as well as the completeness that will identify all possible solutions under the specified constraints and exclude trivial and useless solutions from the perspective of real-life practice. In this paper, I demonstrated an approach that can be adapted to solve most of the constraint satisfaction problems especially within the context of cryptarithmatic puzzles. This method will also perform forward checking to have early backtracking and prevent searching the entire search tree exhaustively.