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

This Sudoku Puzzle has 72 steps and it is solved using Hidden Single, Locked Pair, Naked Single, Locked Candidates Type 1 (Pointing), Locked Candidates Type 2 (Claiming), undefined, Empty Rectangle, Uniqueness Test 3, Naked Pair, AIC, Skyscraper, Full House techniques.

Try To Solve This Puzzle

Solution Steps:

  1. Row 1 / Column 5 → 5 (Hidden Single)
  2. Row 4 / Column 2 → 5 (Hidden Single)
  3. Row 9 / Column 9 → 5 (Hidden Single)
  4. Row 2 / Column 3 → 5 (Hidden Single)
  5. Locked Pair: 4,9 in r3c23 => r1c13,r3c179<>4, r1c13,r2c2,r3c1579<>9
  6. Row 2 / Column 2 → 2 (Naked Single)
  7. Row 1 / Column 3 → 3 (Naked Single)
  8. Row 1 / Column 9 → 4 (Hidden Single)
  9. Row 3 / Column 9 → 1 (Hidden Single)
  10. Locked Candidates Type 1 (Pointing): 9 in b2 => r456c6<>9
  11. Locked Candidates Type 1 (Pointing): 2 in b8 => r456c5<>2
  12. Locked Candidates Type 2 (Claiming): 6 in c9 => r4c8,r5c7<>6
  13. 2-String Kite: 7 in r6c8,r7c5 (connected by r7c7,r8c8) => r6c5<>7
  14. Empty Rectangle: 8 in b8 (r3c57) => r8c7<>8
  15. Uniqueness Test 3: 4/9 in r3c23,r8c23 => r8c78<>7, r8c8<>3, r8c8<>8
  16. Row 6 / Column 8 → 7 (Hidden Single)
  17. Row 7 / Column 7 → 7 (Hidden Single)
  18. Row 6 / Column 4 → 2 (Hidden Single)
  19. Naked Pair: 6,8 in r24c4 => r1c4<>6, r8c4<>8
  20. XYZ-Wing: 6/8/9 in r28c8,r3c7 => r1c8<>6
  21. AIC: 8 8- r3c5 =8= r3c7 -8- r9c7 -4- r9c1 =4= r4c1 =2= r4c8 -2- r1c8 -9- r8c8 -6- r2c8 =6= r2c4 =8= r4c4 -8 => r2c4,r45c5<>8
  22. Row 2 / Column 4 → 6 (Naked Single)
  23. Row 4 / Column 4 → 8 (Naked Single)
  24. Row 8 / Column 8 → 6 (Hidden Single)
  25. Skyscraper: 8 in r8c6,r9c8 (connected by r2c68) => r9c5<>8
  26. AIC: 3 3- r4c6 -4- r4c1 =4= r9c1 -4- r9c7 =4= r8c7 =9= r7c9 -9- r6c9 -3 => r4c89,r6c56<>3
  27. Row 9 / Column 8 → 3 (Hidden Single)
  28. Row 2 / Column 8 → 8 (Hidden Single)
  29. Row 2 / Column 6 → 9 (Full House)
  30. Row 3 / Column 7 → 6 (Naked Single)
  31. Row 3 / Column 1 → 7 (Naked Single)
  32. Row 1 / Column 1 → 6 (Naked Single)
  33. Row 3 / Column 5 → 8 (Naked Single)
  34. Row 8 / Column 6 → 8 (Hidden Single)
  35. Locked Candidates Type 1 (Pointing): 3 in b8 => r45c5<>3
  36. Naked Pair: 6,9 in r4c59 => r4c18<>9
  37. Row 4 / Column 8 → 2 (Naked Single)
  38. Row 1 / Column 8 → 9 (Full House)
  39. Row 1 / Column 7 → 2 (Full House)
  40. Skyscraper: 9 in r7c1,r8c7 (connected by r5c17) => r7c9,r8c23<>9
  41. Row 7 / Column 9 → 8 (Naked Single)
  42. Row 9 / Column 7 → 4 (Naked Single)
  43. Row 8 / Column 7 → 9 (Full House)
  44. Row 5 / Column 7 → 8 (Full House)
  45. Row 9 / Column 1 → 2 (Naked Single)
  46. Row 7 / Column 3 → 9 (Naked Single)
  47. Row 9 / Column 5 → 1 (Naked Single)
  48. Row 9 / Column 3 → 8 (Full House)
  49. Row 3 / Column 3 → 4 (Naked Single)
  50. Row 3 / Column 2 → 9 (Full House)
  51. Row 7 / Column 1 → 3 (Naked Single)
  52. Row 7 / Column 5 → 2 (Full House)
  53. Row 6 / Column 5 → 9 (Naked Single)
  54. Row 8 / Column 4 → 7 (Naked Single)
  55. Row 1 / Column 4 → 1 (Full House)
  56. Row 8 / Column 5 → 3 (Full House)
  57. Row 1 / Column 6 → 7 (Full House)
  58. Row 8 / Column 3 → 1 (Naked Single)
  59. Row 5 / Column 3 → 2 (Full House)
  60. Row 8 / Column 2 → 4 (Full House)
  61. Row 4 / Column 1 → 4 (Naked Single)
  62. Row 5 / Column 1 → 9 (Full House)
  63. Row 4 / Column 5 → 6 (Naked Single)
  64. Row 5 / Column 5 → 7 (Full House)
  65. Row 6 / Column 9 → 3 (Naked Single)
  66. Row 4 / Column 6 → 3 (Naked Single)
  67. Row 4 / Column 9 → 9 (Full House)
  68. Row 5 / Column 9 → 6 (Full House)
  69. Row 6 / Column 2 → 1 (Naked Single)
  70. Row 5 / Column 2 → 3 (Full House)
  71. Row 5 / Column 6 → 1 (Full House)
  72. Row 6 / Column 6 → 4 (Full House)
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