Find the Cat #210: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (10)Orange (11)Yellow (9)Green (9)Teal (15)Blue (1)Purple (18)Pink (10)Brown (12)Grey (5)

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: R1C1. Put a cat there.
  2. Wherever the cat in the Red region ends up, it rules out R2C3, R2C5, R3C3, R3C5, R4C4, R5C4 and 5 more. Cross those squares out.
  3. Wherever the cat in the Pink region ends up, it rules out R9C3. Cross that square out.
  4. Wherever the cat in the Brown region ends up, it rules out R9C2. Cross that square out.
  5. Wherever the cat in the Pink region ends up, it rules out R10C5, R10C6, R10C7, R10C8, R10C9 and R10C10. Cross those squares out.
  6. Wherever the cat in the Grey region ends up, it rules out R8C9, R8C10, R9C5, R9C6, R9C7 and R9C8. Cross those squares out.
  7. The Red and Yellow regions can only use rows 2 and 3, so rows 2 and 3 are already spoken for. Cross out R2C6, R3C2, R3C6, R3C7 and R3C8.
  8. The Pink and Brown regions can only use columns 2 and 3, so columns 2 and 3 are already spoken for. Cross out R4C2, R4C3, R5C3, R6C3 and R7C3.
  9. The Orange region has only one open square left: R4C5. Put a cat there.
  10. The Red region has only one open square left: R2C4. Put a cat there.
  11. The Green region has only one open square left: R7C6. Put a cat there.
  12. Column 7 has only one open square left: R5C7. Put a cat there.
  13. Column 8 has only one open square left: R8C8. Put a cat there.
  14. The Brown region has only one open square left: R6C2. Put a cat there.
  15. The Pink region has only one open square left: R10C3. Put a cat there.
  16. The Grey region has only one open square left: R9C10. Put a cat there.
  17. The Yellow region has only one open square left: R3C9. 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 18 squares. It can be solved in 17 deduction steps using grouped row/column/region deductions.

A useful habit is to mark squares you have ruled out. Tap a square once for a cross and twice for a cat -- crosses cost nothing and make later deductions much easier to spot.

Every puzzle on this site has exactly one solution that can be reached by pure deduction. If you find yourself guessing, look again for a region or line with only a few open squares left.

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