9
2
5
6
4
1
3
8
7
8
6
7
2
3
5
1
9
4
3
4
1
9
7
8
2
6
5
1
9
2
8
7
3
4
5
6
7
8
3
4
5
6
9
2
1
4
5
6
1
9
2
5
1
9
2
3
8
7
6
4
6
4
2
5
7
9
3
1
8
6
1
4
5
2
9

This Sudoku Puzzle has 55 steps and it is solved using Naked Single, Hidden Single, Locked Candidates Type 1 (Pointing), Locked Candidates Type 2 (Claiming), Remote Pair, Skyscraper, undefined, Uniqueness Test 3, Full House, Bivalue Universal Grave + 1, Give Up techniques.

Naked Single Explanation
Hidden Single Explanation
Locked Candidates Explanation
Locked Candidates Explanation
Full House Explanation
Try To Solve This Puzzle

Solution Steps:

  1. Row 8 / Column 1 → 2 (Naked Single)
  2. Row 8 / Column 9 → 4 (Naked Single)
  3. Row 8 / Column 3 → 8 (Naked Single)
  4. Row 1 / Column 4 → 8 (Hidden Single)
  5. Row 5 / Column 4 → 4 (Hidden Single)
  6. Row 5 / Column 3 → 3 (Hidden Single)
  7. Row 5 / Column 8 → 9 (Naked Single)
  8. Row 3 / Column 8 → 6 (Naked Single)
  9. Row 4 / Column 8 → 5 (Naked Single)
  10. Row 9 / Column 2 → 6 (Hidden Single)
  11. Row 7 / Column 6 → 2 (Hidden Single)
  12. Row 5 / Column 9 → 2 (Hidden Single)
  13. Row 1 / Column 8 → 4 (Hidden Single)
  14. Row 3 / Column 2 → 8 (Hidden Single)
  15. Row 9 / Column 6 → 8 (Hidden Single)
  16. Row 3 / Column 3 → 7 (Hidden Single)
  17. Row 1 / Column 5 → 6 (Hidden Single)
  18. Row 6 / Column 2 → 5 (Hidden Single)
  19. Locked Candidates Type 1 (Pointing): 3 in b2 => r2c7<>3
  20. Locked Candidates Type 1 (Pointing): 9 in b4 => r4c4<>9
  21. Locked Candidates Type 1 (Pointing): 3 in b9 => r7c5<>3
  22. Locked Candidates Type 2 (Claiming): 9 in c5 => r2c46,r3c4<>9
  23. Remote Pair: 1/4 r2c3 -4- r9c3 -1- r7c2 -4- r7c5 => r2c5<>1
  24. Skyscraper: 1 in r1c9,r2c6 (connected by r6c69) => r2c7<>1
  25. 2-String Kite: 1 in r1c1,r5c7 (connected by r4c1,r5c2) => r1c7<>1
  26. Uniqueness Test 3: 3/8 in r6c78,r7c78 => r1c7<>9
  27. Row 1 / Column 7 → 3 (Naked Single)
  28. Row 1 / Column 9 → 1 (Naked Single)
  29. Row 1 / Column 1 → 9 (Full House)
  30. Row 4 / Column 1 → 1 (Full House)
  31. Row 4 / Column 4 → 7 (Naked Single)
  32. Row 4 / Column 2 → 9 (Full House)
  33. Row 5 / Column 2 → 7 (Full House)
  34. Row 5 / Column 7 → 1 (Full House)
  35. Locked Candidates Type 1 (Pointing): 1 in b1 => r2c46<>1
  36. Row 2 / Column 6 → 5 (Naked Single)
  37. Row 8 / Column 6 → 9 (Naked Single)
  38. Row 6 / Column 6 → 1 (Full House)
  39. Row 8 / Column 4 → 5 (Full House)
  40. Row 6 / Column 4 → 9 (Full House)
  41. Bivalue Universal Grave + 1 => r9c5<>3, r9c5<>4
  42. Row 9 / Column 5 → 1 (Naked Single)
  43. Row 3 / Column 5 → 9 (Naked Single)
  44. Row 7 / Column 5 → 4 (Naked Single)
  45. Row 9 / Column 4 → 3 (Full House)
  46. Row 9 / Column 3 → 4 (Full House)
  47. Row 2 / Column 5 → 3 (Full House)
  48. Row 7 / Column 2 → 1 (Full House)
  49. Row 2 / Column 3 → 1 (Full House)
  50. Row 2 / Column 2 → 4 (Full House)
  51. Row 3 / Column 7 → 2 (Naked Single)
  52. Row 2 / Column 7 → 9 (Full House)
  53. Row 2 / Column 4 → 2 (Full House)
  54. Row 3 / Column 4 → 1 (Full House)
  55. Give Up: Don't know how to proceed!
Show More...