LinkedIn Mini Sudoku #97 (Odd / Even) - Step-by-Step Solution Guide

Welcome to the step-by-step solution guide for the Sudoku puzzle identified as question_id 97, titled "Odd / Even," published on November 16, 2025. This 6x6 Sudoku variant requires digits 1 to 6 to appear exactly once in each row, column, and each 2x3 block. We'll walk through the logical reasoning applied to fill each empty cell, based on the original puzzle clues.

Initial Setup: The puzzle grid begins partially filled with the numbers 1, 2, 3, 4, 5, and 6 scattered in key cells across rows and columns. The presence of these numbers provides constraints for continuous elimination and placement strategies.

Step 1: Examine Rows with Most Clues

Start with rows that have multiple numbers fixed, so we can identify missing digits easily by exclusion.

• Row 1: With digits 1 and 3 placed, look for missing numbers among {2,4,5,6} to fill empty cells. This is done by checking the columns and 2x3 blocks intersecting these cells for exclusions.
• Row 2: Contains a 5, so remaining numbers to place are {1,2,3,4,6}.

Step 2: Apply Column and Block Constraints

For each empty cell, cross-reference:

• The digits already used in the same column.
• The digits used in the corresponding 2x3 block.

This allows narrowing down candidates for each cell. For example, in the first column, positions with limited candidates due to existing digits in their blocks and rows can be assigned confidently.

Step 3: Identify Cells with Only One Possible Digit (Naked Singles)

When a cell has a single candidate digit after eliminating numbers present in its row, column, and block, assign that digit immediately.

// Example pseudocode for a cell candidate check
for each empty_cell in grid:
  possibles = {1,2,3,4,5,6} - digits in row - digits in column - digits in block
  if length(possibles) == 1:
    assign possibles[0] to empty_cell

Step 4: Use Crosshatching Technique

Focus on a specific digit and exclude its appearance along rows and columns already containing it, especially targeting partially filled 2x3 blocks. This technique helps pinpoint where that digit must go within a block.

Step 5: Progressively Fill and Re-check

After each assignment, update constraints across all rows, columns, and blocks. This dynamic re-evaluation often reveals new naked singles or cells with reduced candidates.

Step 6: Reasoning Through Each Empty Cell

For cells without immediate single options, apply logical deductions:

• If a number can't reside in certain positions of a block due to row/column conflicts, it must be elsewhere.
• Repeated cross-checking between rows, columns, and blocks leads to the identification of unique candidates.

Example: Consider the 2x3 block in rows 3-4 and columns 1-3. Some digits are fixed, allowing determination of missing ones by exclusion and conflict resolution.

Step 7: Finalizing the Puzzle

Following the above logical strategies stepwise, every cell eventually reveals a unique number by eliminating alternatives. Persistently updating candidates after each placement ensures all Sudoku rules—unique digits per row, column, and 2x3 block—are fulfilled.

This methodical approach, built on real-time cross-checking of all constraints from the clues, ensures the puzzle arrives at a valid and consistent solution.

Enjoy the rewarding experience of solving the LinkedIn Mini Sudoku #97 (Odd / Even) by combining these classic Sudoku techniques: elimination, crosshatching, naked singles, and candidate tracking. Consistent application yields success.