Sudaku - Pattern-driven sudoku

Find a pattern, let your logic ripple across the grid, and focus on your next insight. Sudaku is your tireless sudoku workhorse - it handles all the grunt work while you do the thinking. Spot something? It fills in every obvious consequence. Express patterns using constraints like alldifferent, one-of, and value elimination. Your rules, your strategy, your glory. 9×9 and 16×16 puzzles included.

---