Find the Cat #291: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (8)Orange (15)Yellow (1)Green (2)Teal (7)Blue (9)Purple (18)Pink (15)Brown (13)Grey (12)

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 Yellow region has only one open square left: R5C5. Put a cat there.
  2. Wherever the cat in the Red region ends up, it rules out R8C3. Cross that square out.
  3. Wherever the cat in the Green region ends up, it rules out R1C1, R1C2, R1C3, R1C4, R1C6, R1C7 and 3 more. Cross those squares out.
  4. The Blue region has only one open square left: R2C6. Put a cat there.
  5. Wherever the cat in the Red region ends up, it rules out R3C4, R7C3, R9C4 and R10C4. Cross those squares out.
  6. The Brown region has only one open square left: R3C8. Put a cat there.
  7. Wherever the cat in the Grey region ends up, it rules out R7C10. Cross that square out.
  8. Wherever the cat in row 10 ends up, it rules out R9C2. Cross that square out.
  9. The Green and Grey regions can only use columns 9 and 10, so columns 9 and 10 are already spoken for. Cross out R7C9, R8C9, R8C10, R9C9, R9C10, R10C9 and 1 more.
  10. The Pink region has only one open square left: R6C7. Put a cat there.
  11. The Grey region has only one open square left: R4C10. Put a cat there.
  12. The Orange region has only one open square left: R7C2. Put a cat there.
  13. The Red region has only one open square left: R8C4. Put a cat there.
  14. The Green region has only one open square left: R1C9. Put a cat there.
  15. The Purple region has only one open square left: R10C3. Put a cat there.
  16. The Teal region has only one open square left: R9C1. 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 18 squares. It can be solved in 16 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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