Find the Cat #252: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (7)Orange (14)Yellow (1)Green (12)Teal (17)Blue (12)Purple (7)Pink (12)Brown (8)Grey (10)

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 Yellow region has only one open square left: R9C4. Put a cat there.
  2. Wherever the cat in the Green region ends up, it rules out R7C6, R8C6 and R10C7. Cross those squares out.
  3. Wherever the cat in the Red region ends up, it rules out R7C9. Cross that square out.
  4. Wherever the cat in the Brown region ends up, it rules out R6C8. Cross that square out.
  5. Wherever the cat in the Red region ends up, it rules out R8C7. Cross that square out.
  6. The Green region has only one open square left: R10C6. Put a cat there.
  7. Wherever the cat in the Purple region ends up, it rules out R1C5, R2C5, R3C5 and R4C5. Cross those squares out.
  8. Wherever the cat in the Grey region ends up, it rules out R1C10, R2C10, R3C10, R4C10, R5C10, R6C10 and 1 more. Cross those squares out.
  9. The Red and Grey regions can only use rows 7 and 8, so rows 7 and 8 are already spoken for. Cross out R7C1, R7C2, R7C3, R7C5, R8C1 and R8C2.
  10. The Pink region has only one open square left: R6C1. Put a cat there.
  11. The Purple region has only one open square left: R5C5. Put a cat there.
  12. The Orange region has only one open square left: R4C2. Put a cat there.
  13. The Brown region has only one open square left: R3C8. Put a cat there.
  14. The Red region has only one open square left: R7C7. Put a cat there.
  15. The Teal region has only one open square left: R1C9. Put a cat there.
  16. The Blue region has only one open square left: R2C3. Put a cat there.
  17. The Grey region has only one open square left: R8C10. Put a cat there.

About this puzzle

Where to start: the Yellow region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Yellow) to 17 squares. It can be solved in 17 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.

More hard puzzles