GridMew1Check row 4
row 4 has only one remaining candidate: row 4, column 3. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 2 other cells.Let the fourth row settle the top edge
Original puzzle gm-5-0002
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.
Two fixed cats near opposite lower corners already occupy columns 5 and 1. Inspect row 4 between them: their neighboring cells remove the apparent space at both ends, leaving a central starting move.
5×5 · 2 fixed cats · 3 explained deductions. Region sizes: A: 7 · B: 4 · C: 7 · D: 3 · E: 4.
A deduction worth checking
After r4c3, row 2 resolves at r2c2. That placement removes r1c2, while column 3 and the fixed column-5 cat already restrict the top row.
A move to double-check · r1c3
The first new cat at r4c3 excludes r1c3 even though they do not touch. They share column 3. An adjacency-only scan would miss this long-range effect.
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.
A A A A A B B A A C B B D C C E E D C C E E D C C
Fixed cats: row 3, column 5; row 5, column 1. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check row 2
row 2 has only one remaining candidate: row 2, column 2. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 1 other cells.3Check row 1
row 1 has only one remaining candidate: row 1, column 4. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. 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: r1c4, r2c2, r3c5, r4c3, r5c1.
Try another puzzle
Use a middle-row single to separate the ends
gm-5-0009 · 5×5 · intro
Practice single-candidate placements on another 5×5 board.
Read this walkthrough →A bottom-right cat clears a path through row 3
gm-6-0005 · 6×6 · intro
Transfer single-candidate placements to a 6×6 grid; compare how the candidates change.
Read this walkthrough →A shared neighborhood settles the right edge
gm-6-0007 · 6×6 · challenge
Compare this route with shared-neighbor exclusions, and check why that different rule is needed.
Read this walkthrough →