Find the Cat #220: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (3)Orange (8)Yellow (17)Green (7)Teal (8)Blue (9)Purple (1)Pink (14)Brown (16)Grey (17)

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 Purple region has only one open square left: R6C2. Put a cat there.
  2. Wherever the cat in the Red region ends up, it rules out R1C8 and R2C10. Cross those squares out.
  3. Wherever the cat in the Green region ends up, it rules out R7C5. Cross that square out.
  4. The Red and Blue regions can only use columns 9 and 10, so columns 9 and 10 are already spoken for. Cross out R3C9, R3C10, R7C9, R7C10, R8C9, R8C10 and 4 more.
  5. The Teal region has only one open square left: R8C8. Put a cat there.
  6. Wherever the cat in the Orange region ends up, it rules out R4C3, R4C4 and R4C5. Cross those squares out.
  7. Wherever the cat in the Green region ends up, it rules out R9C6 and R10C6. Cross those squares out.
  8. Wherever the cat in row 3 ends up, it rules out R2C6. Cross that square out.
  9. Wherever the cat in row 7 ends up, it rules out R3C6, R4C6 and R5C6. Cross those squares out.
  10. Wherever the cat in the Pink region ends up, it rules out R5C4. Cross that square out.
  11. The Orange region has only one open square left: R4C1. Put a cat there.
  12. Wherever the cat in the Blue region ends up, it rules out R5C5 and R5C7. Cross those squares out.
  13. The Pink region has only one open square left: R7C4. Put a cat there.
  14. The Green region has only one open square left: R9C5. Put a cat there.
  15. Column 6 has only one open square left: R1C6. Put a cat there.
  16. The Red region has only one open square left: R2C9. Put a cat there.
  17. The Blue region has only one open square left: R5C10. Put a cat there.
  18. The Brown region has only one open square left: R3C3. Put a cat there.
  19. The Grey region has only one open square left: R10C7. Put a cat there.

About this puzzle

Where to start: the Purple region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Purple) to 17 squares. It can be solved in 19 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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