I want to create a Sudoku puzzle, and I want it to be of moderate difficulty.

There's a specific pattern I want to include, called the X-Wing pattern:

enter image description here enter image description here

This occurs when two numbers form locked pairs - the two squares are the only ones of a specific number in a row or column. As a result, the other in that row or column can be eliminated.

I want to create Sudoku puzzles which require the use of this pattern to be solved, partially because I want to practice it, but also partially because my friends and I like to swap difficult puzzles.

Currently, I use the "generate a random Sudoku and remove numbers" method to create new puzzles, then check in a solver to see whether it's valid and what patterns are used.

How do I go about modifying or creating a new generation process to ensure I will create puzzles with the X-Wing pattern?


I don't think you can force someone to use the X-Wing technique. There are several techniques to eliminate clues. If they eliminate the 7s in your example by a different technique , then the X-Wing will be gone.

Eliminating clues in a different order will also cause the grid to look different. This site has been around for years and may give some insight: http://www.setbb.com/sudoku/


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.