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

This Sudoku Puzzle has 81 steps and it is solved using Hidden Single, Locked Candidates Type 1 (Pointing), Naked Pair, Naked Single, Locked Candidates Type 2 (Claiming), Naked Triple, Hidden Pair, undefined, Sue de Coq, Full House techniques.

Try To Solve This Puzzle

Solution Steps:

  1. Row 4 / Column 4 → 1 (Hidden Single)
  2. Row 2 / Column 9 → 6 (Hidden Single)
  3. Row 8 / Column 5 → 8 (Hidden Single)
  4. Row 6 / Column 4 → 7 (Hidden Single)
  5. Row 3 / Column 9 → 4 (Hidden Single)
  6. Locked Candidates Type 1 (Pointing): 5 in b3 => r4c8<>5
  7. Locked Candidates Type 1 (Pointing): 5 in b4 => r78c3<>5
  8. Locked Candidates Type 1 (Pointing): 6 in b4 => r79c3<>6
  9. Locked Candidates Type 1 (Pointing): 6 in b5 => r1c5<>6
  10. Locked Candidates Type 1 (Pointing): 9 in b8 => r13c4<>9
  11. Naked Pair: 2,8 in r4c17 => r4c358<>2, r4c89<>8
  12. Row 4 / Column 8 → 7 (Naked Single)
  13. Row 4 / Column 9 → 5 (Naked Single)
  14. Row 6 / Column 3 → 5 (Hidden Single)
  15. Row 6 / Column 5 → 6 (Hidden Single)
  16. Row 4 / Column 5 → 4 (Naked Single)
  17. Row 4 / Column 3 → 6 (Naked Single)
  18. Row 3 / Column 5 → 2 (Hidden Single)
  19. Locked Candidates Type 1 (Pointing): 2 in b5 => r5c38<>2
  20. Locked Candidates Type 1 (Pointing): 2 in b4 => r78c1<>2
  21. Locked Candidates Type 1 (Pointing): 3 in b5 => r5c8<>3
  22. Locked Candidates Type 1 (Pointing): 2 in b6 => r8c7<>2
  23. Locked Candidates Type 2 (Claiming): 3 in c5 => r1c46,r23c6,r3c4<>3
  24. Row 1 / Column 4 → 6 (Naked Single)
  25. Row 3 / Column 4 → 5 (Naked Single)
  26. Row 2 / Column 8 → 5 (Hidden Single)
  27. Locked Candidates Type 2 (Claiming): 8 in c9 => r79c8<>8
  28. Naked Triple: 1,3,9 in r2c157 => r2c36<>1, r2c3<>3, r2c3<>9
  29. Naked Triple: 4,7,9 in r13c2,r2c3 => r2c1,r3c3<>9, r3c3<>7
  30. Locked Candidates Type 1 (Pointing): 9 in b1 => r5789c2<>9
  31. Hidden Pair: 5,6 in r7c26 => r7c2<>7, r7c2<>8, r7c6<>2, r7c6<>3
  32. XY-Wing: 4/8/9 in r15c2,r5c8 => r1c8<>9
  33. W-Wing: 1/3 in r1c8,r2c1 connected by 3 in r12c5 => r2c7<>1
  34. Row 2 / Column 1 → 1 (Hidden Single)
  35. Row 3 / Column 3 → 3 (Naked Single)
  36. Sue de Coq: r7c123 - {2356789} (r7c48 - {239}, r89c2 - {5678}) => r8c3<>7, r7c9<>3, r7c9<>9
  37. XY-Chain: 3 3- r2c7 -9- r2c5 -3- r1c5 -9- r1c2 -4- r5c2 -8- r5c8 -9- r6c9 -3 => r6c7<>3
  38. Row 6 / Column 9 → 3 (Hidden Single)
  39. Locked Candidates Type 2 (Claiming): 9 in c9 => r79c8,r8c7<>9
  40. Naked Triple: 1,2,3 in r179c8 => r3c8<>1
  41. W-Wing: 3/9 in r2c7,r8c1 connected by 9 in r6c17 => r8c7<>3
  42. Row 8 / Column 7 → 1 (Naked Single)
  43. Row 2 / Column 7 → 3 (Hidden Single)
  44. Row 1 / Column 8 → 1 (Naked Single)
  45. Row 2 / Column 5 → 9 (Naked Single)
  46. Row 1 / Column 5 → 3 (Full House)
  47. Row 1 / Column 6 → 4 (Naked Single)
  48. Row 1 / Column 2 → 9 (Full House)
  49. Row 2 / Column 6 → 7 (Naked Single)
  50. Row 2 / Column 3 → 4 (Full House)
  51. Row 3 / Column 2 → 7 (Full House)
  52. Row 3 / Column 6 → 1 (Full House)
  53. Row 5 / Column 3 → 9 (Naked Single)
  54. Row 8 / Column 2 → 5 (Naked Single)
  55. Row 5 / Column 8 → 8 (Naked Single)
  56. Row 6 / Column 1 → 2 (Naked Single)
  57. Row 6 / Column 7 → 9 (Full House)
  58. Row 4 / Column 7 → 2 (Full House)
  59. Row 4 / Column 1 → 8 (Full House)
  60. Row 5 / Column 2 → 4 (Full House)
  61. Row 3 / Column 7 → 8 (Full House)
  62. Row 3 / Column 8 → 9 (Full House)
  63. Row 8 / Column 3 → 2 (Naked Single)
  64. Row 7 / Column 2 → 6 (Naked Single)
  65. Row 9 / Column 2 → 8 (Full House)
  66. Row 7 / Column 3 → 7 (Naked Single)
  67. Row 9 / Column 3 → 1 (Full House)
  68. Row 8 / Column 6 → 3 (Naked Single)
  69. Row 7 / Column 6 → 5 (Naked Single)
  70. Row 9 / Column 9 → 9 (Naked Single)
  71. Row 7 / Column 9 → 8 (Naked Single)
  72. Row 8 / Column 9 → 7 (Full House)
  73. Row 8 / Column 1 → 9 (Full House)
  74. Row 7 / Column 1 → 3 (Full House)
  75. Row 5 / Column 6 → 2 (Naked Single)
  76. Row 5 / Column 4 → 3 (Full House)
  77. Row 9 / Column 6 → 6 (Full House)
  78. Row 9 / Column 4 → 2 (Naked Single)
  79. Row 7 / Column 4 → 9 (Full House)
  80. Row 7 / Column 8 → 2 (Full House)
  81. Row 9 / Column 8 → 3 (Full House)
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