Cats & Dogs #111: 8x8 Grid Puzzle (Medium)

medium

Tap a square: 🐱 cat → 🐶 dog → clear

0 / 64 · 0:00
🐱 4 cats and 🐶 4 dogs in every row and column = same   × different

Can you finish the grid? Cats and dogs must balance in every line, no animal may appear three times in a row, and = / × signs tell you whether two neighbors match.

  • Exactly 4 cats and 4 dogs in every row and every column.
  • Never three of the same animal in a row, across or down.
  • An = between two squares means the same animal; a × means different animals.

Step-by-step solution

Squares are written as R<row>C<column>, counting from the top-left.

  1. The = clue between R1C2 and R2C2 means they are the same. R1C2 is a dog, so R2C2 is a dog.
  2. The = clue between R5C8 and R5C7 means they are the same. R5C8 is a dog, so R5C7 is a dog.
  3. The = clue between R6C4 and R6C3 means they are the same. R6C4 is a dog, so R6C3 is a dog.
  4. The × clue between R6C3 and R7C3 means they are different. R6C3 is a dog, so R7C3 is a cat.
  5. R2C2 and R2C4 are both dogs with one square between them, so R2C3 must be a cat.
  6. R5C7 and R5C8 are both dogs, so R5C6 must be a cat (no three in a row).
  7. R6C3 and R6C4 are both dogs, so R6C2 must be a cat (no three in a row).
  8. R6C3 and R6C4 are both dogs, so R6C5 must be a cat (no three in a row).
  9. R6C5 and R6C6 are both cats, so R6C7 must be a dog (no three in a row).
  10. R8C7 and R8C8 are both dogs, so R8C6 must be a cat (no three in a row).
  11. The × clue between R8C6 and R8C5 means they are different. R8C6 is a cat, so R8C5 is a dog.
  12. The × clue between R8C5 and R7C5 means they are different. R8C5 is a dog, so R7C5 is a cat.
  13. R7C3 and R7C5 are both cats with one square between them, so R7C4 must be a dog.
  14. R1C2 and R2C2 are both dogs, so R3C2 must be a cat (no three in a row).
  15. R2C4 and R4C4 are both dogs with one square between them, so R3C4 must be a cat.
  16. R3C2 and R3C4 are both cats with one square between them, so R3C3 must be a dog.
  17. R4C4 and R6C4 are both dogs with one square between them, so R5C4 must be a cat.
  18. R5C3 and R5C4 are both cats, so R5C2 must be a dog (no three in a row).
  19. R5C3 and R5C4 are both cats, so R5C5 must be a dog (no three in a row).
  20. R6C4 and R7C4 are both dogs, so R8C4 must be a cat (no three in a row).
  21. R5C6 and R6C6 are both cats, so R4C6 must be a dog (no three in a row).
  22. R4C4 and R4C6 are both dogs with one square between them, so R4C5 must be a cat.
  23. R5C6 and R6C6 are both cats, so R7C6 must be a dog (no three in a row).
  24. R5C7 and R6C7 are both dogs, so R4C7 must be a cat (no three in a row).
  25. The × clue between R4C7 and R3C7 means they are different. R4C7 is a cat, so R3C7 is a dog.
  26. R5C7 and R6C7 are both dogs, so R7C7 must be a cat (no three in a row).
  27. R5C8 and R6C8 are both dogs, so R4C8 must be a cat (no three in a row).
  28. R5C8 and R6C8 are both dogs, so R7C8 must be a cat (no three in a row).
  29. Row 5 already has its 4 dogs, so R5C1 must be cats.
  30. Row 6 already has its 4 dogs, so R6C1 must be cats.
  31. R5C1 and R6C1 are both cats, so R4C1 must be a dog (no three in a row).
  32. R5C1 and R6C1 are both cats, so R7C1 must be a dog (no three in a row).
  33. Row 7 already has its 4 cats, so R7C2 must be dogs.
  34. Column 2 already has its 4 dogs, so R4C2 must be cats.
  35. Row 4 already has its 4 cats, so R4C3 must be dogs.
  36. Column 2 already has its 4 dogs, so R8C2 must be cats.
  37. R8C2 and R8C4 are both cats with one square between them, so R8C3 must be a dog.
  38. Row 8 already has its 4 dogs, so R8C1 must be cats.
  39. Column 3 already has its 4 dogs, so R1C3 must be cats.
  40. Column 4 already has its 4 dogs, so R1C4 must be cats.
  41. R1C3 and R1C4 are both cats, so R1C5 must be a dog (no three in a row).
  42. Column 7 already has its 4 dogs, so R1C7 and R2C7 must be cats.
  43. The = clue between R2C7 and R2C8 means they are the same. R2C7 is a cat, so R2C8 is a cat.
  44. R2C7 and R2C8 are both cats, so R2C6 must be a dog (no three in a row).
  45. R2C4 and R2C6 are both dogs with one square between them, so R2C5 must be a cat.
  46. R2C5 and R4C5 are both cats with one square between them, so R3C5 must be a dog.
  47. R3C5 and R3C7 are both dogs with one square between them, so R3C6 must be a cat.
  48. R2C8 and R4C8 are both cats with one square between them, so R3C8 must be a dog.
  49. Row 2 already has its 4 cats, so R2C1 must be dogs.
  50. R2C1 and R4C1 are both dogs with one square between them, so R3C1 must be a cat.
  51. Column 1 already has its 4 cats, so R1C1 must be dogs.
  52. Column 6 already has its 4 cats, so R1C6 must be dogs.
  53. Row 1 already has its 4 dogs, so R1C8 must be cats.

About this puzzle

This 8×8 grid starts with 10 filled squares and 8 = / × clues. It can be solved in 53 steps using pairs, gaps, counts and clues.

Start with the clues and the squares already filled in. An = or × next to a known animal gives you its neighbor immediately.

When every square is filled, press Check Answer. The grid is verified against the stored solution and any broken rule is named.

More medium puzzles