Find the Cat #218: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (12)Orange (6)Yellow (7)Green (10)Teal (6)Blue (1)Purple (12)Pink (12)Brown (11)Grey (23)

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 Blue region has only one open square left: R10C4. Put a cat there.
  2. Wherever the cat in the Red region ends up, it rules out R8C2. Cross that square out.
  3. Wherever the cat in the Yellow region ends up, it rules out R6C2. Cross that square out.
  4. Wherever the cat in the Teal region ends up, it rules out R8C8 and R9C6. Cross those squares out.
  5. Wherever the cat in column 9 ends up, it rules out R2C10. Cross that square out.
  6. The Red and Teal regions can only use rows 8 and 9, so rows 8 and 9 are already spoken for. Cross out R8C5, R8C6, R8C9, R8C10, R9C9 and R9C10.
  7. Wherever the cat in the Brown region ends up, it rules out R6C6. Cross that square out.
  8. The Red, Yellow and Pink regions can only use columns 1, 2 and 3, so columns 1, 2 and 3 are already spoken for. Cross out R1C1, R1C2, R1C3, R2C2, R2C3 and R3C3.
  9. Wherever the cat in the Purple region ends up, it rules out R2C5, R5C5, R6C5 and R7C5. Cross those squares out.
  10. Wherever the cat in the Orange region ends up, it rules out R5C6. Cross that square out.
  11. The Brown region has only one open square left: R7C6. Put a cat there.
  12. The Orange region has only one open square left: R4C7. Put a cat there.
  13. The Yellow region has only one open square left: R6C1. Put a cat there.
  14. The Teal region has only one open square left: R9C8. Put a cat there.
  15. The Red region has only one open square left: R8C3. Put a cat there.
  16. The Pink region has only one open square left: R3C2. Put a cat there.
  17. The Purple region has only one open square left: R1C5. Put a cat there.
  18. The Green region has only one open square left: R2C9. Put a cat there.
  19. The Grey region has only one open square left: R5C10. Put a cat there.

About this puzzle

Where to start: the Blue region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Blue) to 23 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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