Find the Cat #215: 10x10 Grid Puzzle (Hard)

hard

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

0 / 10 cats · 0:00
Red (10)Orange (9)Yellow (7)Green (9)Teal (7)Blue (1)Purple (12)Pink (18)Brown (15)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 Blue region has only one open square left: R1C6. Put a cat there.
  2. The Orange region has only one open square left: R3C5. Put a cat there.
  3. Wherever the cat in the Red region ends up, it rules out R2C1, R2C2 and R2C3. Cross those squares out.
  4. Wherever the cat in the Yellow region ends up, it rules out R5C8. Cross that square out.
  5. Wherever the cat in the Teal region ends up, it rules out R6C3. Cross that square out.
  6. Wherever the cat in the Brown region ends up, it rules out R4C1 and R5C3. Cross those squares out.
  7. Wherever the cat in the Teal region ends up, it rules out R7C4, R8C4, R9C4 and R10C4. Cross those squares out.
  8. The Yellow and Brown regions can only use rows 4 and 5, so rows 4 and 5 are already spoken for. Cross out R4C9, R4C10, R5C1, R5C4, R5C9 and R5C10.
  9. The Teal region has only one open square left: R6C4. Put a cat there.
  10. Wherever the cat in the Purple region ends up, it rules out R7C9. Cross that square out.
  11. Wherever the cat in the Grey region ends up, it rules out R4C2, R5C2, R8C1, R8C3 and R10C2. Cross those squares out.
  12. The Brown region has only one open square left: R4C3. Put a cat there.
  13. The Yellow region has only one open square left: R5C7. Put a cat there.
  14. Wherever the cat in the Purple region ends up, it rules out R2C10, R8C9, R9C10 and R10C10. Cross those squares out.
  15. Wherever the cat in the Green region ends up, it rules out R9C8 and R10C8. Cross those squares out.
  16. Wherever the cat in row 10 ends up, it rules out R7C1 and R9C1. Cross those squares out.
  17. Column 1 has only one open square left: R10C1. Put a cat there.
  18. Row 9 has only one open square left: R9C9. Put a cat there.
  19. The Red region has only one open square left: R2C8. Put a cat there.
  20. The Purple region has only one open square left: R7C10. Put a cat there.
  21. The Grey region has only one open square left: R8C2. Put a cat there.

About this puzzle

Where to start: the Blue region is a single square, so its cat is already decided. Its 10 color regions range from 1 square (Blue) to 18 squares. It can be solved in 21 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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