Cats & Dogs #133: 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 R2C1 and R1C1 means they are the same. R2C1 is a dog, so R1C1 is a dog.
  2. The × clue between R2C5 and R1C5 means they are different. R2C5 is a cat, so R1C5 is a dog.
  3. The = clue between R4C5 and R4C6 means they are the same. R4C5 is a dog, so R4C6 is a dog.
  4. The = clue between R6C6 and R6C5 means they are the same. R6C6 is a dog, so R6C5 is a dog.
  5. The × clue between R6C5 and R7C5 means they are different. R6C5 is a dog, so R7C5 is a cat.
  6. The = clue between R8C1 and R8C2 means they are the same. R8C1 is a cat, so R8C2 is a cat.
  7. R2C5 and R2C6 are both cats, so R2C4 must be a dog (no three in a row).
  8. R2C5 and R2C6 are both cats, so R2C7 must be a dog (no three in a row).
  9. R4C5 and R4C6 are both dogs, so R4C4 must be a cat (no three in a row).
  10. R4C5 and R4C6 are both dogs, so R4C7 must be a cat (no three in a row).
  11. R6C5 and R6C6 are both dogs, so R6C4 must be a cat (no three in a row).
  12. R6C5 and R6C6 are both dogs, so R6C7 must be a cat (no three in a row).
  13. R8C1 and R8C2 are both cats, so R8C3 must be a dog (no three in a row).
  14. R1C1 and R2C1 are both dogs, so R3C1 must be a cat (no three in a row).
  15. The = clue between R3C1 and R3C2 means they are the same. R3C1 is a cat, so R3C2 is a cat.
  16. R3C1 and R3C2 are both cats, so R3C3 must be a dog (no three in a row).
  17. The = clue between R3C3 and R4C3 means they are the same. R3C3 is a dog, so R4C3 is a dog.
  18. R3C3 and R4C3 are both dogs, so R2C3 must be a cat (no three in a row).
  19. R3C3 and R4C3 are both dogs, so R5C3 must be a cat (no three in a row).
  20. R7C3 and R8C3 are both dogs, so R6C3 must be a cat (no three in a row).
  21. R6C3 and R6C4 are both cats, so R6C2 must be a dog (no three in a row).
  22. The = clue between R6C2 and R6C1 means they are the same. R6C2 is a dog, so R6C1 is a dog.
  23. R4C4 and R6C4 are both cats with one square between them, so R5C4 must be a dog.
  24. R4C5 and R6C5 are both dogs with one square between them, so R5C5 must be a cat.
  25. R4C6 and R6C6 are both dogs with one square between them, so R5C6 must be a cat.
  26. R5C5 and R5C6 are both cats, so R5C7 must be a dog (no three in a row).
  27. Row 6 already has its 4 dogs, so R6C8 must be cats.
  28. The = clue between R6C8 and R5C8 means they are the same. R6C8 is a cat, so R5C8 is a cat.
  29. R5C8 and R6C8 are both cats, so R4C8 must be a dog (no three in a row).
  30. R5C8 and R6C8 are both cats, so R7C8 must be a dog (no three in a row).
  31. Row 4 already has its 4 dogs, so R4C1 must be cats.
  32. R3C1 and R4C1 are both cats, so R5C1 must be a dog (no three in a row).
  33. R5C1 and R6C1 are both dogs, so R7C1 must be a cat (no three in a row).
  34. Row 4 already has its 4 dogs, so R4C2 must be cats.
  35. R3C2 and R4C2 are both cats, so R2C2 must be a dog (no three in a row).
  36. R3C2 and R4C2 are both cats, so R5C2 must be a dog (no three in a row).
  37. R5C2 and R6C2 are both dogs, so R7C2 must be a cat (no three in a row).
  38. Row 2 already has its 4 dogs, so R2C8 must be cats.
  39. Column 2 already has its 4 cats, so R1C2 must be dogs.
  40. R1C1 and R1C2 are both dogs, so R1C3 must be a cat (no three in a row).
  41. Column 8 already has its 4 cats, so R1C8 must be dogs.
  42. Row 1 already has its 4 dogs, so R1C4 and R1C6 must be cats.
  43. R1C6 and R2C6 are both cats, so R3C6 must be a dog (no three in a row).
  44. Row 1 already has its 4 dogs, so R1C7 must be cats.
  45. Column 8 already has its 4 cats, so R3C8 must be dogs.
  46. R3C6 and R3C8 are both dogs with one square between them, so R3C7 must be a cat.
  47. Column 7 already has its 4 cats, so R7C7 must be dogs.
  48. R7C7 and R7C8 are both dogs, so R7C6 must be a cat (no three in a row).
  49. R7C5 and R7C6 are both cats, so R7C4 must be a dog (no three in a row).
  50. Column 6 already has its 4 cats, so R8C6 must be dogs.
  51. Column 7 already has its 4 cats, so R8C7 must be dogs.
  52. R8C6 and R8C7 are both dogs, so R8C5 must be a cat (no three in a row).
  53. Row 8 already has its 4 cats, so R8C4 must be dogs.
  54. Column 4 already has its 4 dogs, so R3C4 must be cats.
  55. Row 3 already has its 4 cats, so R3C5 must be dogs.

About this puzzle

This 8×8 grid starts with 8 filled squares and 10 = / × clues. It can be solved in 55 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