GridMew1Check row 4
row 4 has only one remaining candidate: row 4, column 2. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 1 other cells.A short finish between three fixed cats
Original puzzle gm-5-0004
By GridMew · Published 15 October 2026 · Updated 16 October 2026
5 × 5 intro
Read the starting position, follow the deductions, and check the move that is easy to misread.
Puzzle board · starting state
How to approach this board
Coordinates such as r2c3 mean row 2, column 3. Count rows from the top and columns from the left.
The cats at r1c3, r2c1 and r3c4 have already filled three rows, columns and regions. Focus on the two remaining rows instead of trying to reopen a region that already contains its fixed cat.
5×5 · 3 fixed cats · 2 explained deductions. Region sizes: A: 4 · B: 4 · C: 9 · D: 5 · E: 3.
A deduction worth checking
Row 4 has only r4c2. Placing it occupies column 2 and leaves the final bottom-row cat at r5c5.
A move to double-check · r5c2
r5c2 is not rescued by belonging to a different region. The new cat at r4c2 rules it out through their shared column, as well as their immediate contact.
Green marks the cell being discussed, not a cat to place. This is the position before step 1; compare the deduction below.
Read the starting board as text
Each line is one row, left to right. Matching letters belong to the same connected region.
B A A C C B A A C C B B C C C D D C C E D D D E E
Fixed cats: row 1, column 3; row 2, column 1; row 3, column 4. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check row 5
row 5 has only one remaining candidate: row 5, column 5. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 0 other cells.Show solution · reveals all cat positions
The final cats satisfy every row, column and region quota, with no edge or corner contact.
Cat positions: r1c3, r2c1, r3c4, r4c2, r5c5.
Try another puzzle
Check the unused columns against the remaining rows
gm-5-0006 · 5×5 · intro
Practice single-candidate placements on another 5×5 board.
Read this walkthrough →Use the three completed upper rows as constraints
gm-6-0004 · 6×6 · intro
Transfer single-candidate placements to a 6×6 grid; compare how the candidates change.
Read this walkthrough →Let a lower row reserve the right-hand region
gm-8-0002 · 8×8 · challenge
Compare this route with candidate locks, and check why that different rule is needed.
Read this walkthrough →