GridMew1Check row 5
row 5 has only one remaining candidate: row 5, column 1. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 3 other cells.Clear the bottom row, then work upward
Original puzzle gm-5-0029
By GridMew · Published 15 October 2026 · Updated 16 October 2026
5 × 5 practice
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 r4c3 given fills region D and removes its surrounding cells. Row 5 has only r5c1 left. Trace how this one placement changes the rows above rather than choosing inside the large top region.
5×5 · 1 fixed cats · 4 explained deductions. Region sizes: A: 6 · B: 1 · C: 4 · D: 9 · E: 5.
A deduction worth checking
After the column-1 exclusion, row 3 resolves at r3c5. Its column effect removes two upper-right candidates, preparing row 2.
A move to double-check · r2c5
r2c5 is excluded by the new column-5 cat even though it is in a different region. Region borders do not stop row or column constraints.
Green marks the cell being discussed, not a cat to place. This is the position before step 2; 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 C A B A D C E E D D C E E D D C E D D D D
Fixed cats: row 4, column 3. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check row 3
row 3 has only one remaining candidate: row 3, column 5. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 2 other cells.3Check 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 3. Place one cat, then exclude 1 other cells.4Check 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 4. 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
A wide lower region forces a narrow route upward
gm-5-0032 · 5×5 · practice
Practice single-candidate placements on another 5×5 board.
Read this walkthrough →A bottom-left singleton opens a distant column
gm-6-0009 · 6×6 · practice
Transfer single-candidate placements to a 6×6 grid; compare how the candidates change.
Read this walkthrough →Two possible cats, one shared exclusion
gm-5-0001 · 5×5 · challenge
Compare this route with shared-neighbor exclusions, and check why that different rule is needed.
Read this walkthrough →