Find the Cat #275: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (18)Orange (15)Yellow (9)Green (8)Teal (1)Blue (14)Purple (9)Pink (14)Brown (11)Grey (1)

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 Teal region has only one open square left: R7C1. Put a cat there.
  2. The Grey region has only one open square left: R1C9. Put a cat there.
  3. The Green region has only one open square left: R2C6. Put a cat there.
  4. The Yellow region has only one open square left: R3C2. Put a cat there.
  5. Wherever the cat in the Purple region ends up, it rules out R4C7 and R6C8. Cross those squares out.
  6. Wherever the cat in the Red region ends up, it rules out R5C4. Cross that square out.
  7. Wherever the cat in the Brown region ends up, it rules out R4C4, R5C5 and R6C3. Cross those squares out.
  8. The Red region has only one open square left: R4C5. Put a cat there.
  9. Wherever the cat in the Orange region ends up, it rules out R9C3. Cross that square out.
  10. Wherever the cat in column 10 ends up, it rules out R9C7, R9C8, R10C7 and R10C8. Cross those squares out.
  11. The Purple and Brown regions can only use rows 5 and 6, so rows 5 and 6 are already spoken for. Cross out R5C10 and R6C10.
  12. The Orange and Brown regions can only use columns 3 and 4, so columns 3 and 4 are already spoken for. Cross out R10C3 and R10C4.
  13. Row 10 has only one open square left: R10C10. Put a cat there.
  14. Row 9 has only one open square left: R9C4. Put a cat there.
  15. The Brown region has only one open square left: R5C3. Put a cat there.
  16. The Purple region has only one open square left: R6C7. Put a cat there.
  17. The Blue region has only one open square left: R8C8. Put a cat there.

About this puzzle

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

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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