How to solve this 8×8 logic puzzle
A
B
C
D
E
F
G
H
1
2
3
4
5
6
7
8
1
2🐱
3
🐱
4
🐱
🐱
5
🐱
6
🐱
7🐱
8🐱
This 8×8 board rates as gentle (difficulty score 319). Solving it from scratch takes 19 logical steps, using 3 techniques: Single cell, Row/column exclusion, Adjacency clear. Every step below is forced: nothing here is a guess.
- First, place a marker at E8. Region has exactly one open cell left. Placing here clears the rest of row 8, column E, and its region. Placing here also clears its 2 touching neighbours.
- Next, place a marker at B7. Region has exactly one open cell left. Placing here clears the rest of row 7, column B, and its region. Placing here also clears its 2 touching neighbours.
- Then, place a marker at F5. Region has exactly one open cell left. Placing here clears the rest of row 5, column F, and its region. Placing here also clears its 2 touching neighbours.
- After that, place a marker at D1. Region has exactly one open cell left. Placing here clears the rest of row 1, column D, and its region. Placing here also clears its 1 touching neighbour.
- Now, place a marker at A2. Region has exactly one open cell left. Placing here clears the rest of row 2, column A, and its region.
- From there, place a marker at H6. Region has exactly one open cell left. Placing here clears the rest of row 6, column H, and its region.
- Following that, place a marker at G3. Region has exactly one open cell left. Placing here clears the rest of row 3, column G, and its region.
- Finally, place a marker at C4. Region has exactly one open cell left.
This was a gentle solve: every step followed directly from placing a marker and clearing its row, column and region. ∎