GridMew1Check column 1
column 1 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 5 other cells.A column-first route reaches the lower-right regions
Original puzzle gm-8-0011
By GridMew · Published 15 October 2026 · Updated 16 October 2026
8 × 8 intro
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 givens in columns 2 and 4 leave column 1 with r1c1. After that top-row cat, inspect column 3 next. This route begins with line scans rather than choosing the smallest colored region.
8×8 · 2 fixed cats · 6 explained deductions. Region sizes: A: 2 · B: 4 · C: 14 · D: 4 · E: 4 · F: 13 · G: 17 · H: 6.
A deduction worth checking
After r2c3, E resolves at r5c8. Filling E removes its lower-right candidates, while column 8 and the neighborhood shrink C.
A move to double-check · r8c8
r8c8 is not close to r5c8, but they share column 8 and region E. Either quota is enough; neither requires immediate contact.
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 B B C C C C G B B F F C C C G G F F D D C C G G G F D D C C G G G F F C C E G G F F F C E E G G G F F H E H G G G F H H H H
Fixed cats: row 7, column 2; row 6, column 4. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check column 3
column 3 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 2. Place one cat, then exclude 3 other cells.3Check region E
region E has only one remaining candidate: row 5, column 8. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. Place one cat, then exclude 6 other cells.4Check region C
region C has only one remaining candidate: row 3, column 7. 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 4
row 4 has only one remaining candidate: row 4, 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 8
row 8 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 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, r2c3, r3c7, r4c5, r5c8, r6c4, r7c2, r8c6.
Try another puzzle
An upper-left region leads to a distant column single
gm-8-0004 · 8×8 · intro
Practice single-candidate placements on another 8×8 board.
Read this walkthrough →A bottom-right cat clears a path through row 3
gm-6-0005 · 6×6 · intro
Transfer single-candidate placements to a 6×6 grid; compare how the candidates change.
Read this walkthrough →A shared neighborhood settles the right edge
gm-6-0007 · 6×6 · challenge
Compare this route with shared-neighbor exclusions, and check why that different rule is needed.
Read this walkthrough →