Find the Cat #169: 8x8 Grid Puzzle (Medium)
mediumTap a square: ✕ (ruled out) → 🐱 (cat) → clear
A 8x8 logic grid, 8 colors, 8 cats. Work out where each cat sits using nothing but the rules -- there is only one correct layout and no guessing is needed.
- One cat in every row and every column.
- One cat in every color region.
- Cats can’t touch — not even diagonally.
Step-by-step solution
Squares are written as R<row>C<column>, counting from the top-left. Cross out the squares listed, and place a cat wherever a step says so.
- The Blue region has only one open square left: R8C7. Put a cat there.
- Wherever the cat in the Orange region ends up, it rules out R1C5, R2C5, R3C5, R4C5, R6C4 and R6C6. Cross those squares out.
- Wherever the cat in the Yellow region ends up, it rules out R6C5, R7C2 and R7C3. Cross those squares out.
- Wherever the cat in the Green region ends up, it rules out R4C2. Cross that square out.
- Wherever the cat in the Purple region ends up, it rules out R6C2. Cross that square out.
- Wherever the cat in the Yellow region ends up, it rules out R5C4. Cross that square out.
- The Orange, Yellow and Purple regions can only use rows 5, 6 and 7, so rows 5, 6 and 7 are already spoken for. Cross out R5C6, R5C8 and R6C8.
- Wherever the cat in row 6 ends up, it rules out R5C2 and R5C3. Cross those squares out.
- Wherever the cat in the Purple region ends up, it rules out R1C1, R2C1, R3C1 and R4C1. Cross those squares out.
- Wherever the cat in the Green region ends up, it rules out R2C3 and R3C4. Cross those squares out.
- Wherever the cat in column 2 ends up, it rules out R3C6. Cross that square out.
- Wherever the cat in column 6 ends up, it rules out R4C8. Cross that square out.
- Wherever the cat in column 8 ends up, it rules out R1C6 and R2C6. Cross those squares out.
- Column 6 has only one open square left: R4C6. Put a cat there.
- The Orange region has only one open square left: R7C5. Put a cat there.
- The Yellow region has only one open square left: R6C3. Put a cat there.
- The Green region has only one open square left: R3C2. Put a cat there.
- The Teal region has only one open square left: R1C4. Put a cat there.
- The Purple region has only one open square left: R5C1. Put a cat there.
- The Pink region has only one open square left: R2C8. Put a cat there.
About this puzzle
Where to start: the Blue region is a single square, so its cat is already decided. Its 8 color regions range from 1 square (Blue) to 13 squares. It can be solved in 20 deduction steps using grouped row/column/region deductions.
Start with the region that is a single square -- its cat has nowhere else to go. Cross out that cat's whole row, column and neighbors, then move on to the next-smallest regions: with only a couple of squares each, they leave very little room.
Stuck? Open the step-by-step solution below -- each step names the row, column or color involved, so you can use it as a hint and then finish the puzzle yourself.