GridMew1Check 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 1. Place one cat, then exclude 8 other cells.Puzzle gm-8-0004
8 × 8 intro
Take this puzzle one clear step at a time.
Try the puzzle yourself, then explore how the deductions build.
Puzzle board · starting state
Your starting point
This original 8×8 board has 8 connected regions and 2 fixed cats. The smallest region is A, with 2 cells. Start by ruling out every other cell in each fixed cat’s row, column and region, plus its immediate neighbors.
The verified route below uses 6 forced placements and 0 candidate-elimination steps after the givens. Region sizes: A: 2 · B: 2 · C: 16 · D: 14 · E: 11 · F: 7 · G: 8 · H: 4. These are observations about this board, not a guarantee that a smaller region always contains the next move.
Read each diagram in sequence. Cats and × marks in the before-state come from earlier deductions. Green outlines identify the current observation. Open the final answer only when you want the spoiler.
Step-by-step walkthrough
2Check column 8
column 8 has only one remaining candidate: row 2, column 8. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 4 other cells.3Check column 6
column 6 has only one remaining candidate: row 8, column 6. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. Place one cat, then exclude 2 other cells.4Check region E
region E has only one remaining candidate: row 5, column 3. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 4. Place one cat, then exclude 4 other cells.5Check row 6
row 6 has only one remaining candidate: row 6, column 5. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 5. Place one cat, then exclude 1 other cells.6Check row 3
row 3 has only one remaining candidate: row 3, column 4. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 6. 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, r2c8, r3c4, r4c7, r5c3, r6c5, r7c2, r8c6.