Suirodoku — The First Playable Graeco-Latin Sudoku Square

🎮 Play Suirodoku online

What is Suirodoku?

Suirodoku is a 9×9 puzzle that combines Sudoku with colors. Each cell contains a unique digit-color pair. It's Sudoku, but harder and more beautiful.

How it works

• Each row, column, and 3×3 block contains all 9 digits and all 9 colors
• Each of the 81 digit-color pairs appears exactly once in the grid
• Every cell has a unique identity — no two cells are the same

Key Features

• 🧩 Free online puzzle game
• 🌈 9 colors × 9 digits = 81 unique pairs
• 📐 Based on Euler's Graeco-Latin squares (1782)
• 🏆 Leaderboard and difficulty levels

Unique Solving Techniques

• Rainbow Technique — track a digit across all 9 colors
• Chromatic Circle — track a color across all 9 digits

Research Papers

• Suirodoku: A Graeco-Latin Sudoku Square — Overview, existence proof, and Bijection Theorem
• Suirodoku: A CSP Formalization — Formal constraint model
• The God Digit Problem — Critical symbols and Dichotomy Theorem
• Unified paper on Zenodo — DOI: 10.5281/zenodo.18625970

Links

• 🌐 Play online
• 📄 Zenodo
• 🔬 ResearchGate
• 🎓 Academia.edu
• 🆔 ORCID