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.

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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