Find the Cat #205: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (1)Orange (9)Yellow (8)Green (20)Teal (9)Blue (10)Purple (7)Pink (6)Brown (9)Grey (21)

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 Red region has only one open square left: R8C1. Put a cat there.
  2. Wherever the cat in the Teal region ends up, it rules out R10C3. Cross that square out.
  3. The Purple region has only one open square left: R10C2. Put a cat there.
  4. The Teal region has only one open square left: R9C4. Put a cat there.
  5. Wherever the cat in the Blue region ends up, it rules out R1C3, R2C3, R3C3, R6C3 and R7C3. Cross those squares out.
  6. The Orange region has only one open square left: R7C5. Put a cat there.
  7. Wherever the cat in the Green region ends up, it rules out R5C7, R5C8, R6C9 and R6C10. Cross those squares out.
  8. Wherever the cat in the Brown region ends up, it rules out R4C6, R4C7 and R5C9. Cross those squares out.
  9. Wherever the cat in the Yellow region ends up, it rules out R3C10. Cross that square out.
  10. Wherever the cat in row 3 ends up, it rules out R2C8 and R2C9. Cross those squares out.
  11. Wherever the cat in row 2 ends up, it rules out R1C7. Cross that square out.
  12. The Blue and Brown regions can only use rows 4 and 5, so rows 4 and 5 are already spoken for. Cross out R4C9, R4C10 and R5C10.
  13. Wherever the cat in the Yellow region ends up, it rules out R3C6, R3C7 and R4C8. Cross those squares out.
  14. The Brown region has only one open square left: R5C6. Put a cat there.
  15. The Green region has only one open square left: R6C8. Put a cat there.
  16. The Yellow region has only one open square left: R3C9. Put a cat there.
  17. The Blue region has only one open square left: R4C3. Put a cat there.
  18. The Pink region has only one open square left: R1C10. Put a cat there.
  19. The Grey region has only one open square left: R2C7. Put a cat there.

About this puzzle

Where to start: the Red region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Red) to 21 squares. It can be solved in 19 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.

When you fill the last cat, press Check Answer -- the grid is verified against the stored solution and any broken rule is named so you know where to look.

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