Find the Cat #226: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (4)Orange (13)Yellow (10)Green (16)Teal (11)Blue (20)Purple (13)Pink (1)Brown (3)Grey (9)

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 Pink region has only one open square left: R4C3. Put a cat there.
  2. Wherever the cat in the Red region ends up, it rules out R2C9. Cross that square out.
  3. Wherever the cat in the Brown region ends up, it rules out R6C9. Cross that square out.
  4. The Red, Teal and Purple regions can only use rows 1, 2 and 3, so rows 1, 2 and 3 are already spoken for. Cross out R2C2, R2C5, R3C1 and R3C5.
  5. Wherever the cat in the Yellow region ends up, it rules out R5C1, R5C9 and R5C10. Cross those squares out.
  6. The Brown region has only one open square left: R6C10. Put a cat there.
  7. The Red region has only one open square left: R1C9. Put a cat there.
  8. Wherever the cat in the Green region ends up, it rules out R7C1, R7C2, R7C6, R7C7, R7C8, R8C4 and 1 more. Cross those squares out.
  9. The Grey region has only one open square left: R8C8. Put a cat there.
  10. The Orange region has only one open square left: R10C7. Put a cat there.
  11. Row 3 has only one open square left: R3C6. Put a cat there.
  12. The Yellow region has only one open square left: R5C5. Put a cat there.
  13. The Green region has only one open square left: R7C4. Put a cat there.
  14. The Teal region has only one open square left: R2C1. Put a cat there.
  15. The Blue region has only one open square left: R9C2. Put a cat there.

About this puzzle

Where to start: the Pink region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Pink) to 20 squares. It can be solved in 15 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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