Solution for Hard Sudoku #4212459867318

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

This Sudoku Puzzle has 61 steps and it is solved using Hidden Single, Locked Triple, Naked Single, Locked Candidates Type 1 (Pointing), Naked Pair, undefined, Skyscraper, Full House techniques.

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

Solution Steps:

  1. Row 2 / Column 2 → 2 (Hidden Single)
  2. Locked Triple: 2,4,5 in r7c456 => r7c37,r8c46,r9c5<>4, r7c7,r9c5<>5, r8c46<>2
  3. Row 9 / Column 5 → 6 (Naked Single)
  4. Row 3 / Column 5 → 2 (Naked Single)
  5. Locked Candidates Type 1 (Pointing): 8 in b2 => r3c3<>8
  6. Locked Candidates Type 1 (Pointing): 7 in b8 => r8c2<>7
  7. Locked Candidates Type 1 (Pointing): 8 in b8 => r8c78<>8
  8. Naked Pair: 4,5 in r17c5 => r46c5<>5, r6c5<>4
  9. X-Wing: 9 r37 c37 => r2c37,r458c7,r568c3<>9
  10. Skyscraper: 9 in r2c1,r5c2 (connected by r25c8) => r46c1<>9
  11. Row 2 / Column 1 → 9 (Hidden Single)
  12. Row 3 / Column 7 → 9 (Hidden Single)
  13. Row 7 / Column 7 → 3 (Naked Single)
  14. Row 7 / Column 3 → 9 (Naked Single)
  15. Row 2 / Column 3 → 1 (Hidden Single)
  16. Row 8 / Column 3 → 4 (Naked Single)
  17. Row 8 / Column 2 → 1 (Naked Single)
  18. Row 8 / Column 7 → 6 (Naked Single)
  19. Row 9 / Column 2 → 7 (Naked Single)
  20. Row 9 / Column 1 → 3 (Full House)
  21. Row 1 / Column 2 → 6 (Naked Single)
  22. Row 3 / Column 3 → 3 (Naked Single)
  23. Row 4 / Column 2 → 9 (Naked Single)
  24. Row 5 / Column 2 → 4 (Full House)
  25. Row 1 / Column 3 → 8 (Naked Single)
  26. Row 1 / Column 1 → 7 (Full House)
  27. Row 3 / Column 6 → 8 (Naked Single)
  28. Row 3 / Column 4 → 6 (Full House)
  29. Row 4 / Column 5 → 1 (Naked Single)
  30. Row 6 / Column 3 → 5 (Naked Single)
  31. Row 5 / Column 3 → 6 (Full House)
  32. Row 8 / Column 6 → 7 (Naked Single)
  33. Row 4 / Column 1 → 8 (Naked Single)
  34. Row 6 / Column 1 → 1 (Full House)
  35. Row 6 / Column 5 → 9 (Naked Single)
  36. Row 5 / Column 6 → 5 (Naked Single)
  37. Row 8 / Column 4 → 8 (Naked Single)
  38. Row 4 / Column 7 → 5 (Naked Single)
  39. Row 6 / Column 9 → 2 (Naked Single)
  40. Row 4 / Column 6 → 2 (Naked Single)
  41. Row 4 / Column 9 → 6 (Full House)
  42. Row 5 / Column 4 → 7 (Naked Single)
  43. Row 6 / Column 4 → 4 (Full House)
  44. Row 6 / Column 8 → 8 (Full House)
  45. Row 5 / Column 7 → 1 (Naked Single)
  46. Row 5 / Column 8 → 9 (Full House)
  47. Row 2 / Column 7 → 4 (Naked Single)
  48. Row 9 / Column 7 → 8 (Full House)
  49. Row 8 / Column 9 → 9 (Naked Single)
  50. Row 8 / Column 8 → 2 (Full House)
  51. Row 7 / Column 6 → 4 (Naked Single)
  52. Row 2 / Column 6 → 3 (Full House)
  53. Row 2 / Column 4 → 5 (Naked Single)
  54. Row 1 / Column 5 → 4 (Full House)
  55. Row 7 / Column 5 → 5 (Full House)
  56. Row 2 / Column 8 → 6 (Full House)
  57. Row 7 / Column 4 → 2 (Full House)
  58. Row 9 / Column 8 → 5 (Naked Single)
  59. Row 1 / Column 8 → 3 (Full House)
  60. Row 1 / Column 9 → 5 (Full House)
  61. Row 9 / Column 9 → 4 (Full House)
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