Find the Cat #247: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (8)Orange (10)Yellow (18)Green (18)Teal (14)Blue (7)Purple (8)Pink (10)Brown (1)Grey (6)

Can you place all 10 cats? One per row, one per column, one per color -- and keep them at least one square apart in every direction.

  • 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 Brown region has only one open square left: R3C7. Put a cat there.
  2. Wherever the cat in the Purple region ends up, it rules out R5C6 and R7C5. Cross those squares out.
  3. Wherever the cat in row 1 ends up, it rules out R2C2, R2C3, R2C9 and R2C10. Cross those squares out.
  4. Columns 9 and 10 can only use the Yellow and Green regions, so the Yellow and Green regions are already spoken for. Cross out R1C1, R1C2, R1C3, R1C4, R1C5, R1C6 and 5 more.
  5. Wherever the cat in column 8 ends up, it rules out R2C4, R2C5, R4C5, R5C9 and R6C9. Cross those squares out.
  6. Row 2 has only one open square left: R2C1. Put a cat there.
  7. The Grey region has only one open square left: R9C2. Put a cat there.
  8. Wherever the cat in the Blue region ends up, it rules out R10C4, R10C9 and R10C10. Cross those squares out.
  9. Wherever the cat in the Pink region ends up, it rules out R7C4, R8C6, R8C9 and R8C10. Cross those squares out.
  10. Wherever the cat in column 3 ends up, it rules out R4C4, R5C4 and R6C4. Cross those squares out.
  11. Column 4 has only one open square left: R8C4. Put a cat there.
  12. The Orange region has only one open square left: R6C3. Put a cat there.
  13. The Teal region has only one open square left: R5C8. Put a cat there.
  14. The Purple region has only one open square left: R7C6. Put a cat there.
  15. The Green region has only one open square left: R4C10. Put a cat there.
  16. The Yellow region has only one open square left: R1C9. Put a cat there.
  17. The Blue region has only one open square left: R10C5. Put a cat there.

About this puzzle

Where to start: the Brown region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Brown) to 18 squares. It can be solved in 17 deduction steps using grouped row/column/region deductions.

If a row and a color both have only two open squares and share them, those two lines are locked together -- neither can use squares anywhere else.

This is a variation of the Star Battle family of grid puzzles, sometimes also called Queens-style puzzles, with cats in place of stars.

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