The Model and Algorithm to Estimate the Difficulty Levels of Sudoku Puzzles

Abstract

Sudoku is a number placement mathematical puzzle based on logic. The purpose of this paper is to discuss suitable
models and algorithm to generate Sudoku puzzles of varying difficulty. It is generally recognized that hand-made puzzles
are more enjoyable than those generated by computer. Our goal is to establish models to generate Sudoku puzzles of
varying difficulty, which are as enjoyable as hand-made ones. As we believe that puzzles generated by simulating the
design process of hand-made ones will also be of much enjoyment, we established our first model -No Brute-Force.
Brute-Force technique is excluded from this algorithm, for there is no enjoyment in solving puzzles using it. We have
implemented the algorithm with a JAVA program. We conclude that it is possible and reasonable to generate Sudoku
puzzles of varying difficulty as enjoyable as hand-made ones.