Find the Cat #129: 8x8 Grid Puzzle (Medium)

medium

Tap a square: ✕ (ruled out) → 🐱 (cat) → clear

0 / 8 cats · 0:00
Red (10)Orange (7)Yellow (8)Green (6)Teal (9)Blue (13)Purple (1)Pink (10)

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.

  1. The Purple region has only one open square left: R8C8. Put a cat there.
  2. Wherever the cat in the Orange region ends up, it rules out R1C6, R2C6, R3C6, R4C6, R5C6, R6C5 and 2 more. Cross those squares out.
  3. Wherever the cat in the Yellow region ends up, it rules out R7C2. Cross that square out.
  4. Wherever the cat in the Pink region ends up, it rules out R1C7, R2C7 and R4C7. Cross those squares out.
  5. The Green region has only one open square left: R1C5. Put a cat there.
  6. Wherever the cat in the Red region ends up, it rules out R5C3 and R7C4. Cross those squares out.
  7. Wherever the cat in the Yellow region ends up, it rules out R2C1, R3C1, R4C1, R5C1 and R6C2. Cross those squares out.
  8. Wherever the cat in the Blue region ends up, it rules out R3C2. Cross that square out.
  9. Wherever the cat in row 2 ends up, it rules out R3C3 and R3C4. Cross those squares out.
  10. Row 3 has only one open square left: R3C7. Put a cat there.
  11. Wherever the cat in row 4 ends up, it rules out R5C4. Cross that square out.
  12. Row 5 has only one open square left: R5C2. Put a cat there.
  13. The Yellow region has only one open square left: R7C1. Put a cat there.
  14. The Orange region has only one open square left: R6C6. Put a cat there.
  15. The Red region has only one open square left: R4C4. Put a cat there.
  16. The Blue region has only one open square left: R2C3. Put a cat there.

About this puzzle

Where to start: the Purple region is a single square, so its cat is already decided. Its 8 color regions range from 1 square (Purple) to 13 squares. It can be solved in 16 deduction steps using "wherever it goes" eliminations.

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.

When you fill the last cat, press Check Answer -- the grid is verified against the stored solution and any broken rule is named so you know where to look.

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