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

This Sudoku Puzzle has 70 steps and it is solved using Hidden Single, Locked Candidates Type 1 (Pointing), Locked Candidates Type 2 (Claiming), Naked Single, Full House, Naked Triple, Uniqueness Test 4, Hidden Rectangle, Sue de Coq, undefined 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 1 / Column 2 → 2 (Hidden Single)
  2. Row 6 / Column 1 → 5 (Hidden Single)
  3. Row 2 / Column 3 → 7 (Hidden Single)
  4. Row 4 / Column 7 → 7 (Hidden Single)
  5. Row 4 / Column 5 → 2 (Hidden Single)
  6. Row 6 / Column 8 → 2 (Hidden Single)
  7. Row 1 / Column 1 → 8 (Hidden Single)
  8. Row 8 / Column 8 → 7 (Hidden Single)
  9. Row 6 / Column 3 → 8 (Hidden Single)
  10. Row 5 / Column 8 → 8 (Hidden Single)
  11. Row 8 / Column 2 → 8 (Hidden Single)
  12. Row 6 / Column 9 → 9 (Hidden Single)
  13. Row 6 / Column 5 → 4 (Hidden Single)
  14. Locked Candidates Type 1 (Pointing): 5 in b3 => r2c2<>5
  15. Row 3 / Column 2 → 5 (Hidden Single)
  16. Locked Candidates Type 1 (Pointing): 3 in b6 => r2c7<>3
  17. Locked Candidates Type 1 (Pointing): 4 in b6 => r2c9<>4
  18. Locked Candidates Type 1 (Pointing): 5 in b9 => r8c4<>5
  19. Locked Candidates Type 2 (Claiming): 3 in r4 => r5c23<>3
  20. Locked Candidates Type 2 (Claiming): 9 in r8 => r7c23,r9c12<>9
  21. Row 7 / Column 2 → 1 (Naked Single)
  22. Row 4 / Column 1 → 1 (Hidden Single)
  23. Row 4 / Column 9 → 4 (Naked Single)
  24. Row 4 / Column 3 → 3 (Full House)
  25. Naked Triple: 1,5,6 in r2c579 => r2c18<>6, r2c8<>1
  26. Locked Candidates Type 1 (Pointing): 6 in b1 => r3c468<>6
  27. Naked Triple: 1,5,6 in r8c579 => r8c134<>6
  28. Naked Triple: 3,4,6 in r9c124 => r9c6<>3, r9c68<>6
  29. Locked Candidates Type 1 (Pointing): 3 in b8 => r5c4<>3
  30. Uniqueness Test 4: 3/6 in r5c67,r6c67 => r5c67<>6
  31. Hidden Rectangle: 5/6 in r1c46,r7c46 => r7c4<>6
  32. Sue de Coq: r23c1 - {3469} (r8c1 - {39}, r3c3 - {46}) => r2c2<>4, r9c1<>3
  33. XY-Chain: 6 6- r1c8 -4- r2c8 -3- r2c2 -9- r5c2 -4- r9c2 -3- r9c4 -6- r8c5 -1- r2c5 -6 => r1c46,r2c79<>6
  34. Row 1 / Column 6 → 5 (Naked Single)
  35. Row 1 / Column 4 → 4 (Naked Single)
  36. Row 1 / Column 8 → 6 (Full House)
  37. Row 3 / Column 4 → 7 (Naked Single)
  38. Row 7 / Column 8 → 9 (Naked Single)
  39. Row 3 / Column 6 → 1 (Naked Single)
  40. Row 2 / Column 5 → 6 (Full House)
  41. Row 8 / Column 5 → 1 (Full House)
  42. Row 5 / Column 4 → 6 (Naked Single)
  43. Row 7 / Column 6 → 6 (Naked Single)
  44. Row 9 / Column 8 → 1 (Naked Single)
  45. Row 9 / Column 6 → 9 (Naked Single)
  46. Row 5 / Column 9 → 1 (Naked Single)
  47. Row 6 / Column 6 → 3 (Naked Single)
  48. Row 5 / Column 6 → 7 (Full House)
  49. Row 6 / Column 7 → 6 (Full House)
  50. Row 5 / Column 7 → 3 (Full House)
  51. Row 9 / Column 4 → 3 (Naked Single)
  52. Row 7 / Column 3 → 2 (Naked Single)
  53. Row 7 / Column 4 → 5 (Full House)
  54. Row 8 / Column 4 → 2 (Full House)
  55. Row 2 / Column 9 → 5 (Naked Single)
  56. Row 8 / Column 9 → 6 (Full House)
  57. Row 8 / Column 7 → 5 (Full House)
  58. Row 2 / Column 7 → 1 (Full House)
  59. Row 9 / Column 2 → 4 (Naked Single)
  60. Row 9 / Column 1 → 6 (Full House)
  61. Row 8 / Column 3 → 9 (Naked Single)
  62. Row 8 / Column 1 → 3 (Full House)
  63. Row 5 / Column 2 → 9 (Naked Single)
  64. Row 5 / Column 3 → 4 (Full House)
  65. Row 2 / Column 2 → 3 (Full House)
  66. Row 3 / Column 3 → 6 (Full House)
  67. Row 3 / Column 1 → 4 (Naked Single)
  68. Row 2 / Column 1 → 9 (Full House)
  69. Row 2 / Column 8 → 4 (Full House)
  70. Row 3 / Column 8 → 3 (Full House)
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