Find the Cat #222: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (15)Orange (21)Yellow (11)Green (13)Teal (6)Blue (10)Purple (6)Pink (1)Brown (9)Grey (8)

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: R1C5. Put a cat there.
  2. Wherever the cat in the Green region ends up, it rules out R4C7. Cross that square out.
  3. Wherever the cat in the Purple region ends up, it rules out R2C7 and R3C9. Cross those squares out.
  4. Wherever the cat in the Teal region ends up, it rules out R5C10. Cross that square out.
  5. The Green, Teal and Purple regions can only use rows 2, 3 and 4, so rows 2, 3 and 4 are already spoken for. Cross out R2C1, R2C2, R2C3, R3C1, R3C2, R3C3 and 6 more.
  6. Wherever the cat in the Grey region ends up, it rules out R5C1, R5C2, R5C3, R5C8 and R5C9. Cross those squares out.
  7. Columns 1 and 2 can only use the Orange and Blue regions, so the Orange and Blue regions are already spoken for. Cross out R6C3, R6C4, R7C3, R7C4, R8C3, R8C4 and 1 more.
  8. Column 3 has only one open square left: R9C3. Put a cat there.
  9. The Blue region has only one open square left: R10C1. Put a cat there.
  10. The Brown region has only one open square left: R8C8. Put a cat there.
  11. The Purple region has only one open square left: R2C9. Put a cat there.
  12. The Teal region has only one open square left: R4C10. Put a cat there.
  13. The Green region has only one open square left: R3C6. Put a cat there.
  14. The Red region has only one open square left: R6C7. Put a cat there.
  15. The Orange region has only one open square left: R7C2. Put a cat there.
  16. The Grey region has only one open square left: R5C4. 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 21 squares. It can be solved in 16 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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