GridMew1Check region B
region B has only one remaining candidate: row 2, column 1. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 5 other cells.Puzzle gm-5-0001
5 × 5 challenge
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 5×5 board has 5 connected regions and 1 fixed cat. The smallest region is A, with 3 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 4 forced placements and 1 candidate-elimination step after the givens. Region sizes: A: 3 · B: 4 · C: 6 · D: 9 · E: 3. 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
2Exclude common neighbors
The cat in row 3 must occupy one of row 3, column 4; row 3, column 5. Each of row 4, column 4; row 4, column 5 touches every candidate, so none can hold a cat.
Before step 2. Exclude 2 cells; then scan for a new single.3Check row 4
row 4 has only one remaining candidate: row 4, column 2. 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 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 4. Place one cat, then exclude 1 other cells.5Check row 5
row 5 has only one remaining candidate: row 5, column 4. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 5. 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: r1c3, r2c1, r3c5, r4c2, r5c4.