GridMew1Check row 1
row 1 has only one remaining candidate: row 1, column 3. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 0 other cells.Check the unused columns against the remaining rows
Original puzzle gm-5-0006
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.
Three givens occupy rows 2, 3 and 5, with cats in columns 1, 5 and 4. Only rows 1 and 4 remain. The top row is a useful place to combine column quotas with the given cats’ neighborhoods.
5×5 · 3 fixed cats · 2 explained deductions. Region sizes: A: 4 · B: 4 · C: 7 · D: 8 · E: 2.
A deduction worth checking
The first deduction places r1c3. The only other missing cat then belongs at r4c2; this is a short quota finish rather than a candidate-lock exercise.
A move to double-check · r1c2
At the starting position, r1c2 touches the fixed cat at r2c1. A different region label cannot make that corner contact legal.
Green marks the cell being discussed, not a cat to place. This is the starting position after accounting for the fixed cats.
Read the starting board as text
Each line is one row, left to right. Matching letters belong to the same connected region.
B B A A A B B A C C D D C C C D D D C C D D D E E
Fixed cats: row 3, column 5; row 5, column 4; row 2, column 1. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check 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 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, r3c5, r4c2, r5c4.
Try another puzzle
A short finish between three fixed cats
gm-5-0004 · 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 →