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

This Sudoku Puzzle has 77 steps and it is solved using Hidden Single, Locked Candidates Type 1 (Pointing), Naked Single, Locked Candidates Type 2 (Claiming), Sue de Coq, Discontinuous Nice Loop, AIC, Hidden Pair, Continuous Nice Loop, Empty Rectangle, Full House techniques.

Try To Solve This Puzzle

Solution Steps:

  1. Row 3 / Column 1 → 4 (Hidden Single)
  2. Locked Candidates Type 1 (Pointing): 9 in b1 => r2c7<>9
  3. Row 2 / Column 7 → 7 (Naked Single)
  4. Locked Candidates Type 1 (Pointing): 7 in b2 => r56c6<>7
  5. Locked Candidates Type 1 (Pointing): 5 in b4 => r5c456<>5
  6. Locked Candidates Type 1 (Pointing): 4 in b6 => r5c56<>4
  7. Locked Candidates Type 2 (Claiming): 1 in c5 => r4c46,r5c46,r6c46<>1
  8. Sue de Coq: r456c5 - {13456} (r3c5 - {35}, r6c6 - {46}) => r5c46,r6c4<>6, r7c5<>5
  9. Locked Candidates Type 1 (Pointing): 5 in b8 => r24c4<>5
  10. Discontinuous Nice Loop: 2 r1c3 -2- r1c7 -8- r7c7 -4- r7c5 =4= r8c6 -4- r8c2 =4= r9c2 =8= r5c2 =5= r5c3 =1= r1c3 => r1c3<>2
  11. Discontinuous Nice Loop: 2 r3c7 -2- r1c7 -8- r7c7 -4- r7c5 =4= r8c6 -4- r8c2 =4= r9c2 =8= r5c2 -8- r5c6 -9- r5c7 =9= r3c7 => r3c7<>2
  12. Row 3 / Column 7 → 9 (Naked Single)
  13. AIC: 6 6- r7c5 -4- r7c7 -8- r1c7 -2- r3c9 =2= r3c3 -2- r9c3 -6 => r7c13,r9c4<>6
  14. AIC: 2/5 2- r3c3 =2= r3c9 -2- r1c7 -8- r7c7 -4- r7c5 =4= r8c6 -4- r8c2 =4= r9c2 =8= r5c2 =5= r5c3 -5 => r5c3<>2, r3c3<>5
  15. Hidden Pair: 1,5 in r15c3 => r15c3<>3, r1c3<>7, r5c3<>6
  16. Locked Candidates Type 1 (Pointing): 6 in b4 => r9c1<>6
  17. Discontinuous Nice Loop: 1 r1c1 -1- r1c3 -5- r5c3 =5= r5c2 =8= r9c2 =4= r8c2 -4- r8c6 =4= r7c5 -4- r7c7 -8- r1c7 -2- r3c9 =2= r3c3 =7= r1c1 => r1c1<>1
  18. Discontinuous Nice Loop: 3 r3c3 -3- r3c5 -5- r4c5 =5= r4c6 =8= r4c1 -8- r5c2 =8= r9c2 =4= r8c2 -4- r8c6 =4= r7c5 -4- r7c7 -8- r1c7 -2- r3c9 =2= r3c3 => r3c3<>3
  19. Row 7 / Column 3 → 3 (Hidden Single)
  20. Continuous Nice Loop: 2/3/4/7/8 7= r5c8 =4= r5c7 -4- r7c7 -8- r1c7 -2- r3c9 =2= r3c3 =7= r8c3 -7- r8c8 =7= r5c8 =4 => r1c89,r5c8<>2, r5c8<>3, r9c7<>4, r8c9<>7, r9c7<>8
  21. Empty Rectangle: 3 in b6 (r3c59) => r4c5<>3
  22. Discontinuous Nice Loop: 1/5/6 r1c6 =7= r1c1 -7- r7c1 -8- r7c7 =8= r1c7 =2= r3c9 -2- r3c3 -7- r3c6 =7= r1c6 => r1c6<>1, r1c6<>5, r1c6<>6
  23. Row 1 / Column 6 → 7 (Naked Single)
  24. Row 3 / Column 6 → 5 (Naked Single)
  25. Row 3 / Column 5 → 3 (Naked Single)
  26. Row 3 / Column 9 → 2 (Naked Single)
  27. Row 3 / Column 3 → 7 (Full House)
  28. Row 1 / Column 7 → 8 (Naked Single)
  29. Row 7 / Column 7 → 4 (Naked Single)
  30. Row 7 / Column 5 → 6 (Naked Single)
  31. Row 5 / Column 5 → 1 (Naked Single)
  32. Row 7 / Column 4 → 5 (Naked Single)
  33. Row 4 / Column 5 → 5 (Naked Single)
  34. Row 6 / Column 5 → 4 (Full House)
  35. Row 5 / Column 3 → 5 (Naked Single)
  36. Row 5 / Column 7 → 2 (Naked Single)
  37. Row 9 / Column 7 → 1 (Full House)
  38. Row 6 / Column 6 → 6 (Naked Single)
  39. Row 1 / Column 3 → 1 (Naked Single)
  40. Row 4 / Column 8 → 3 (Naked Single)
  41. Row 8 / Column 9 → 6 (Naked Single)
  42. Row 9 / Column 4 → 9 (Naked Single)
  43. Row 2 / Column 6 → 1 (Naked Single)
  44. Row 2 / Column 4 → 6 (Full House)
  45. Row 8 / Column 3 → 2 (Naked Single)
  46. Row 9 / Column 3 → 6 (Full House)
  47. Row 4 / Column 4 → 2 (Naked Single)
  48. Row 8 / Column 4 → 1 (Naked Single)
  49. Row 8 / Column 6 → 4 (Full House)
  50. Row 2 / Column 8 → 5 (Naked Single)
  51. Row 8 / Column 8 → 7 (Naked Single)
  52. Row 8 / Column 2 → 9 (Full House)
  53. Row 9 / Column 1 → 8 (Naked Single)
  54. Row 1 / Column 8 → 6 (Naked Single)
  55. Row 1 / Column 9 → 3 (Full House)
  56. Row 9 / Column 8 → 2 (Naked Single)
  57. Row 5 / Column 8 → 4 (Full House)
  58. Row 7 / Column 9 → 8 (Naked Single)
  59. Row 7 / Column 1 → 7 (Full House)
  60. Row 9 / Column 2 → 4 (Full House)
  61. Row 9 / Column 9 → 5 (Full House)
  62. Row 2 / Column 2 → 3 (Naked Single)
  63. Row 2 / Column 1 → 9 (Full House)
  64. Row 4 / Column 1 → 1 (Naked Single)
  65. Row 1 / Column 1 → 2 (Naked Single)
  66. Row 1 / Column 2 → 5 (Full House)
  67. Row 5 / Column 2 → 8 (Naked Single)
  68. Row 6 / Column 2 → 2 (Full House)
  69. Row 4 / Column 9 → 9 (Naked Single)
  70. Row 4 / Column 6 → 8 (Full House)
  71. Row 5 / Column 6 → 9 (Full House)
  72. Row 6 / Column 1 → 3 (Naked Single)
  73. Row 5 / Column 1 → 6 (Full House)
  74. Row 5 / Column 9 → 7 (Naked Single)
  75. Row 5 / Column 4 → 3 (Full House)
  76. Row 6 / Column 4 → 7 (Full House)
  77. Row 6 / Column 9 → 1 (Full House)
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