Below is a sample puzzle for you to solve. Difficulty: Hard. Estimated time: 15–25 minutes.

For instance, the MOSEK Fusion API documentation includes a Sudoku solver example on page 129 .

: Specific creators, like James Sinclair in his Artisanal Sudoku Vol. 129 , design complex variants that use "Killer Cages," "Nabner Lines," or "Fog of War" rules rather than just standard digits.