Find the Cat #267: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (17)Orange (12)Yellow (4)Green (1)Teal (12)Blue (11)Purple (8)Pink (13)Brown (16)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 Green region has only one open square left: R10C10. Put a cat there.
  2. The Yellow region has only one open square left: R1C9. Put a cat there.
  3. The Grey region has only one open square left: R9C4. Put a cat there.
  4. Wherever the cat in the Blue region ends up, it rules out R2C5, R2C6, R3C1, R3C2 and R3C3. Cross those squares out.
  5. Wherever the cat in the Brown region ends up, it rules out R3C8 and R8C8. Cross those squares out.
  6. Wherever the cat in row 3 ends up, it rules out R4C5 and R4C6. Cross those squares out.
  7. Wherever the cat in the Orange region ends up, it rules out R5C7. Cross that square out.
  8. Wherever the cat in the Purple region ends up, it rules out R7C6. Cross that square out.
  9. Wherever the cat in column 3 ends up, it rules out R6C2. Cross that square out.
  10. The Orange, Purple and Pink regions can only use columns 5, 6 and 7, so columns 5, 6 and 7 are already spoken for. Cross out R3C5 and R3C6.
  11. The Blue region has only one open square left: R2C2. Put a cat there.
  12. Row 3 has only one open square left: R3C7. Put a cat there.
  13. The Pink region has only one open square left: R8C6. Put a cat there.
  14. The Purple region has only one open square left: R6C5. Put a cat there.
  15. The Teal region has only one open square left: R7C3. Put a cat there.
  16. The Brown region has only one open square left: R5C8. Put a cat there.
  17. The Red region has only one open square left: R4C1. Put a cat there.

About this puzzle

Where to start: the Green region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Green) to 17 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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