Sudoku 7398 is a medium-difficulty puzzle published on July 29, 2026. The grid contains 36 given numbers, requiring logical deduction to fill the remaining 45 cells.
Puzzle Layout and Initial Observations
The puzzle follows standard Sudoku rules: each row, column, and 3x3 box must contain digits 1–9 exactly once. The given numbers are distributed evenly across the grid, with no box having fewer than three clues. Key starting points include row 5, which has five given digits, and column 3, which has four.
Step-by-Step Solving Strategy
Begin by scanning for hidden singles. In box 1 (top-left), the digit 7 appears only in cell (2,2) after eliminating possibilities from row 2 and column 2. Similarly, in box 9 (bottom-right), the digit 3 is forced into cell (8,8). Use pencil marks to track candidates for each empty cell.
Next, apply cross-hatching. For example, the digit 5 in row 1 and column 4 restricts the 5 in box 2 to cell (3,5). Continue this process for all digits, focusing on rows and columns with many given numbers.
Advanced Techniques
After basic strategies, you may encounter a naked pair in row 7: cells (7,4) and (7,6) both contain candidates {2,8}. This eliminates 2 and 8 from other cells in row 7, leading to a placement of 4 in cell (7,9).
Use the X-Wing technique on digit 1 in rows 2 and 8, where the only possible columns are 3 and 7. This removes 1 from other cells in those columns, simplifying the puzzle.
Final Solution
With careful application of these methods, the grid is completed. The solution is unique and can be verified by checking all rows, columns, and boxes. For a full solution grid, refer to the original publication.
