Sudoku is a popular logic-based number puzzle that consists of a 9×9 grid, divided into nine 3×3 subgrids (regions). The goal is to fill in the grid so that each row, column, and 3×3 region contains the numbers 1 to 9, without repetition.
Sudoku Rules
- Every row must contain the numbers 1 to 9 without repetition.
- Every column must contain the numbers 1 to 9 without repetition.
- Every 3×3 subgrid must contain the numbers 1 to 9 without repetition.
- Some numbers are already given as clues—use logic to deduce the missing numbers.
Sudoku Difficulty Levels
✅ Easy – Requires simple elimination and basic logic.
✅ Medium – Involves more advanced strategies like “pencil marking.”
✅ Hard – Requires pattern recognition, “naked pairs,” and “hidden singles.”
✅ Expert/Evil – Requires complex techniques like “X-Wing” or “Swordfish” strategies.
Strategies for Solving Sudoku
- Scan Rows, Columns, and Boxes – Look for obvious missing numbers.
- Pencil Marking – Write small possible numbers in empty squares to track options.
- Naked Pairs & Triples – If two or three cells contain the same possible numbers, eliminate those numbers from other cells in the same row, column, or box.
- X-Wing Strategy – Advanced technique to find patterns in rows and columns.
- Trial and Error (Last Resort) – If stuck, use logic-based guessing to see if a number leads to contradictions.
