Find the Cat #229: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (15)Orange (8)Yellow (1)Green (9)Teal (4)Blue (9)Purple (20)Pink (10)Brown (13)Grey (11)

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: R9C6. Put a cat there.
  2. Wherever the cat in the Teal region ends up, it rules out R1C5 and R2C3. Cross those squares out.
  3. Wherever the cat in column 10 ends up, it rules out R2C9. Cross that square out.
  4. The Orange and Teal regions can only use rows 1 and 2, so rows 1 and 2 are already spoken for. Cross out R1C1, R2C1, R2C2, R2C5, R2C7 and R2C10.
  5. Wherever the cat in the Blue region ends up, it rules out R4C3. Cross that square out.
  6. The Teal, Blue, Brown and Grey regions can only use columns 1, 2, 3 and 4, so columns 1, 2, 3 and 4 are already spoken for. Cross out R6C4, R7C1, R7C3, R7C4, R8C1, R8C2 and 1 more.
  7. Wherever the cat in the Pink region ends up, it rules out R3C5, R4C5 and R5C5. Cross those squares out.
  8. Wherever the cat in the Red region ends up, it rules out R7C7. Cross that square out.
  9. Wherever the cat in the Green region ends up, it rules out R10C1, R10C2, R10C3, R10C4 and R10C10. Cross those squares out.
  10. The Brown region has only one open square left: R8C4. Put a cat there.
  11. The Pink region has only one open square left: R6C5. Put a cat there.
  12. Row 2 has only one open square left: R2C8. Put a cat there.
  13. The Green region has only one open square left: R10C9. Put a cat there.
  14. The Red region has only one open square left: R5C7. Put a cat there.
  15. Wherever the cat in the Blue region ends up, it rules out R3C1. Cross that square out.
  16. Column 1 has only one open square left: R4C1. Put a cat there.
  17. The Blue region has only one open square left: R3C3. Put a cat there.
  18. The Teal region has only one open square left: R1C2. Put a cat there.
  19. The Purple region has only one open square left: R7C10. 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 20 squares. It can be solved in 19 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.

Every puzzle on this site has exactly one solution that can be reached by pure deduction. If you find yourself guessing, look again for a region or line with only a few open squares left.

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