GridMew1Check region E
region E has only one remaining candidate: row 5, 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.The bottom-left pair is not an equal choice
Original puzzle gm-5-0008
By GridMew · Published 15 October 2026 · Updated 16 October 2026
5 × 5 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.
Region E contains r4c1 and r5c1. The fixed cat in row 4 rules out the upper cell, forcing the lower one. This is a quota argument about the whole row, not a preference for the board edge.
5×5 · 1 fixed cats · 4 explained deductions. Region sizes: A: 4 · B: 2 · C: 7 · D: 10 · E: 2.
A deduction worth checking
The E cat removes column 1 from the rest of the board. Combined with the r4c4 given, that leaves r3c2 as row 3’s only candidate.
A move to double-check · r3c1
r3c1 is far enough from r5c1 to pass the touching test, but it shares column 1. All four placement checks still apply.
Green marks the cell being discussed, not a cat to place. This is the position before step 1; 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.
C A A D B C A A D B C C C D D E C D D D E C D D D
Fixed cats: row 4, column 4. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check row 3
row 3 has only one remaining candidate: row 3, column 2. 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 row 2
row 2 has only one remaining candidate: row 2, column 5. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. Place one cat, then exclude 1 other cells.4Check row 1
row 1 has only one remaining candidate: row 1, column 3. 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.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, r2c5, r3c2, r4c4, r5c1.
Try another puzzle
Read the bottom-left region through the fixed column
gm-5-0016 · 5×5 · practice
Practice single-candidate placements on another 5×5 board.
Read this walkthrough →A bottom-row single reaches a right-edge region
gm-6-0001 · 6×6 · practice
Transfer single-candidate placements to a 6×6 grid; compare how the candidates change.
Read this walkthrough →Two possible cats, one shared exclusion
gm-5-0001 · 5×5 · challenge
Compare this route with shared-neighbor exclusions, and check why that different rule is needed.
Read this walkthrough →