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.

Naked Single Explanation
Hidden Single Explanation
Hidden Pair Explanation
Locked Candidates Explanation
Locked Candidates Explanation
Full House Explanation
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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