GridMew1Check region B
region B has only one remaining candidate: row 2, column 3. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 13 other cells.A central singleton prepares an upper-left anchor
Original puzzle gm-8-0057
By GridMew · Published 15 October 2026 · Updated 16 October 2026
8 × 8 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.
B is the one-cell region r2c3. Placing it reduces A to r1c1. Together with the bottom-row given, those upper anchors narrow G’s lower-left possibilities.
8×8 · 1 fixed cats · 7 explained deductions. Region sizes: A: 6 · B: 1 · C: 12 · D: 10 · E: 18 · F: 2 · G: 8 · H: 7.
A deduction worth checking
G resolves at r7c4. Its neighborhood removes r6c5, helping the narrow F region settle at r6c7.
A move to double-check · r6c5
r6c5 has a different region label from r7c4, but shares its corner. Treat that local contact separately from the longer column-4 exclusions.
Green marks the cell being discussed, not a cat to place. This is the position before step 3; 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 C C C A E B A C C C D E E E E C C C D G E E E C C D D G G E E E D D D G G G E E E F D H H G G E E F D H H H H H E E D
Fixed cats: row 8, column 2. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check region A
region A has only one remaining candidate: row 1, column 1. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 8 other cells.3Check region G
region G has only one remaining candidate: row 7, column 4. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. Place one cat, then exclude 8 other cells.4Check region F
region F has only one remaining candidate: row 6, column 7. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 4. Place one cat, then exclude 7 other cells.5Check 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 5. Place one cat, then exclude 3 other cells.6Check row 4
row 4 has only one remaining candidate: row 4, column 8. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 6. Place one cat, then exclude 1 other cells.7Check row 3
row 3 has only one remaining candidate: row 3, column 6. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 7. 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: r1c1, r2c3, r3c6, r4c8, r5c5, r6c7, r7c4, r8c2.
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