Find the Cat #209: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (1)Orange (13)Yellow (10)Green (9)Teal (7)Blue (18)Purple (15)Pink (11)Brown (9)Grey (7)

Find the 10 hidden cats. Each row, each column and each colored region holds exactly one, and cats never sit on neighboring squares, diagonals included.

  • 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 Red region has only one open square left: R9C4. Put a cat there.
  2. The Grey region has only one open square left: R10C6. Put a cat there.
  3. Wherever the cat in the Yellow region ends up, it rules out R7C1. Cross that square out.
  4. Wherever the cat in the Green region ends up, it rules out R1C7. Cross that square out.
  5. Wherever the cat in the Teal region ends up, it rules out R1C1, R2C1, R3C1, R4C1, R5C1 and R7C2. Cross those squares out.
  6. Wherever the cat in the Pink region ends up, it rules out R2C7, R3C7, R4C7, R5C7 and R7C8. Cross those squares out.
  7. The Green region has only one open square left: R1C5. Put a cat there.
  8. Wherever the cat in the Brown region ends up, it rules out R3C9. Cross that square out.
  9. Wherever the cat in column 9 ends up, it rules out R3C10. Cross that square out.
  10. The Yellow, Teal and Pink regions can only use rows 6, 7 and 8, so rows 6, 7 and 8 are already spoken for. Cross out R6C3, R6C8, R6C9, R6C10, R7C9, R7C10 and 3 more.
  11. The Orange and Yellow regions can only use columns 2 and 3, so columns 2 and 3 are already spoken for. Cross out R3C3 and R5C3.
  12. The Purple region has only one open square left: R5C8. Put a cat there.
  13. The Blue region has only one open square left: R4C10. Put a cat there.
  14. The Brown region has only one open square left: R2C9. Put a cat there.
  15. The Orange region has only one open square left: R3C2. Put a cat there.
  16. The Yellow region has only one open square left: R7C3. Put a cat there.
  17. The Pink region has only one open square left: R8C7. Put a cat there.
  18. The Teal region has only one open square left: R6C1. Put a cat there.

About this puzzle

Where to start: the Red region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Red) to 18 squares. It can be solved in 18 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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