Find the Cat #212: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (12)Orange (10)Yellow (10)Green (1)Teal (9)Blue (3)Purple (16)Pink (18)Brown (8)Grey (13)

Every row, every column and every color region needs exactly one cat -- but no two cats may touch, not even diagonally. This puzzle is a 10x10 grid with 10 colored regions.

  • 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 Green region has only one open square left: R3C3. Put a cat there.
  2. Wherever the cat in the Blue region ends up, it rules out R5C9 and R7C10. Cross those squares out.
  3. Wherever the cat in row 10 ends up, it rules out R9C2. Cross that square out.
  4. The Blue and Brown regions can only use rows 5 and 6, so rows 5 and 6 are already spoken for. Cross out R5C2, R5C4, R5C5, R5C6, R5C7, R5C8 and 4 more.
  5. The Red, Yellow and Grey regions can only use rows 1, 2 and 4, so rows 1, 2 and 4 are already spoken for. Cross out R1C7, R1C8, R2C7, R2C8, R4C7 and R4C8.
  6. Wherever the cat in the Purple region ends up, it rules out R7C1, R7C2, R7C4, R7C5, R7C8, R7C9 and 2 more. Cross those squares out.
  7. Wherever the cat in column 8 ends up, it rules out R8C4, R8C5, R9C7 and R9C9. Cross those squares out.
  8. Wherever the cat in the Orange region ends up, it rules out R8C1 and R8C2. Cross those squares out.
  9. The Red and Teal regions can only use columns 1 and 2, so columns 1 and 2 are already spoken for. Cross out R5C1, R6C1 and R6C2.
  10. The Brown region has only one open square left: R6C4. Put a cat there.
  11. The Blue region has only one open square left: R5C10. Put a cat there.
  12. Wherever the cat in the Orange region ends up, it rules out R9C8. Cross that square out.
  13. Wherever the cat in the Yellow region ends up, it rules out R8C9 and R10C9. Cross those squares out.
  14. The Orange region has only one open square left: R8C8. Put a cat there.
  15. The Purple region has only one open square left: R7C6. Put a cat there.
  16. Column 7 has only one open square left: R10C7. Put a cat there.
  17. The Teal region has only one open square left: R9C1. Put a cat there.
  18. The Red region has only one open square left: R1C2. Put a cat there.
  19. The Yellow region has only one open square left: R2C9. Put a cat there.
  20. The Grey region has only one open square left: R4C5. Put a cat there.

About this puzzle

Where to start: the Green region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Green) to 18 squares. It can be solved in 20 deduction steps using grouped row/column/region deductions.

Look for a color that sits entirely inside one row or one column. Its cat must be in that line, so every other square in that line can be crossed out.

Stuck? Open the step-by-step solution below -- each step names the row, column or color involved, so you can use it as a hint and then finish the puzzle yourself.

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