GridMew1Check row 6
row 6 has only one remaining candidate: row 6, column 1. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 4 other cells.A forced left edge makes the central column readable
Original puzzle gm-8-0052
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.
The given at r5c4 fills E, leaving row 6 with r6c1. Region A at r1c6 then supplies another anchor. These two edges reduce column 5 to a central candidate.
8×8 · 1 fixed cats · 7 explained deductions. Region sizes: A: 1 · B: 5 · C: 22 · D: 1 · E: 26 · F: 4 · G: 2 · H: 3.
A deduction worth checking
Column 5 forces r3c5. Its region-C effect removes several distant candidates, including the upper-right cell r2c8.
A move to double-check · r2c8
r2c8 does not touch r3c5. Both are in C, so the filled region, not adjacency, explains this exclusion.
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.
B B B C C A C C B B C C C C C C F C C C C C C C F E E E C C D C F E E E E C E C F E E E E E E E E E G E E E H E E E G E E E H H
Fixed cats: row 5, column 4. 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 6. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 10 other cells.3Check column 5
column 5 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 3. Place one cat, then exclude 7 other cells.4Check 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 4. Place one cat, then exclude 0 other cells.5Check row 4
row 4 has only one remaining candidate: row 4, column 7. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 5. Place one cat, then exclude 2 other cells.6Check row 7
row 7 has only one remaining candidate: row 7, column 3. 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 8
row 8 has only one remaining candidate: row 8, column 8. 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: r1c6, r2c2, r3c5, r4c7, r5c4, r6c1, r7c3, r8c8.
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