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This Sudoku Puzzle has 90 steps and it is solved using Locked Candidates Type 1 (Pointing), Hidden Rectangle, AIC, Locked Candidates Type 2 (Claiming), Discontinuous Nice Loop, Hidden Single, Skyscraper, Grouped AIC, Empty Rectangle, Naked Single, undefined, Naked Pair, Naked Triple, Jellyfish, Locked Pair, Full House techniques.

Try To Solve This Puzzle

Solution Steps:

  1. Locked Candidates Type 1 (Pointing): 7 in b1 => r3c79<>7
  2. Locked Candidates Type 1 (Pointing): 7 in b4 => r4c46<>7
  3. Locked Candidates Type 1 (Pointing): 9 in b6 => r4c46<>9
  4. Hidden Rectangle: 7/8 in r3c12,r4c12 => r4c2<>8
  5. AIC: 8 8- r2c1 -4- r1c3 =4= r1c9 =7= r7c9 =9= r9c8 -9- r9c2 -8 => r23c2,r7c1<>8
  6. Locked Candidates Type 2 (Claiming): 8 in c2 => r7c3<>8
  7. Discontinuous Nice Loop: 1 r4c2 -1- r6c2 -4- r8c2 =4= r8c1 -4- r2c1 -8- r3c1 -7- r3c2 =7= r4c2 => r4c2<>1
  8. Row 6 / Column 2 → 1 (Hidden Single)
  9. Row 6 / Column 5 → 4 (Hidden Single)
  10. Skyscraper: 4 in r1c9,r5c8 (connected by r15c3) => r2c8,r4c9<>4
  11. AIC: 7 7- r3c1 -8- r2c1 -4- r8c1 =4= r8c2 -4- r4c2 -7 => r3c2,r4c1<>7
  12. Row 3 / Column 1 → 7 (Hidden Single)
  13. Row 4 / Column 2 → 7 (Hidden Single)
  14. Discontinuous Nice Loop: 6 r3c9 -6- r3c2 =6= r2c2 =4= r8c2 =2= r8c8 =6= r8c9 -6- r3c9 => r3c9<>6
  15. Discontinuous Nice Loop: 5 r4c5 -5- r5c5 -8- r7c5 =8= r7c2 -8- r9c2 -9- r9c8 =9= r7c9 =7= r1c9 =4= r2c9 =1= r3c9 -1- r3c5 =1= r4c5 => r4c5<>5
  16. Discontinuous Nice Loop: 8 r4c5 -8- r7c5 =8= r7c2 -8- r9c2 -9- r9c8 =9= r7c9 =7= r1c9 =4= r2c9 =1= r3c9 -1- r3c5 =1= r4c5 => r4c5<>8
  17. Discontinuous Nice Loop: 6 r4c9 -6- r8c9 -5- r9c8 -9- r4c8 =9= r4c9 => r4c9<>6
  18. AIC: 5 5- r4c9 -9- r4c8 =9= r9c8 -9- r9c2 -8- r7c2 =8= r7c5 -8- r5c5 -5 => r4c46,r5c8<>5
  19. Discontinuous Nice Loop: 5 r5c4 -5- r5c5 -8- r7c5 =8= r7c2 -8- r9c2 -9- r9c8 =9= r4c8 =4= r5c8 =6= r5c6 =7= r5c4 => r5c4<>5
  20. Hidden Rectangle: 7/8 in r5c46,r9c46 => r9c6<>8
  21. Discontinuous Nice Loop: 5 r5c6 -5- r5c5 -8- r7c5 =8= r7c2 -8- r9c2 -9- r9c8 =9= r4c8 =4= r5c8 =6= r5c6 => r5c6<>5
  22. Grouped AIC: 5 5- r4c9 -9- r4c8 =9= r9c8 -9- r9c2 -8- r9c4 =8= r7c5 -8- r5c5 -5- r6c46 =5= r6c7 -5 => r4c78<>5
  23. Discontinuous Nice Loop: 5 r7c7 -5- r6c7 =5= r4c9 =9= r7c9 =7= r7c7 => r7c7<>5
  24. Empty Rectangle: 5 in b5 (r36c7) => r3c5<>5
  25. Discontinuous Nice Loop: 7/8 r5c6 =6= r5c8 =4= r5c3 -4- r1c3 =4= r1c9 =7= r1c7 -7- r7c7 -2- r8c8 =2= r8c2 =4= r2c2 =6= r3c2 -6- r3c7 =6= r4c7 -6- r4c6 =6= r5c6 => r5c6<>7, r5c6<>8
  26. Row 5 / Column 6 → 6 (Naked Single)
  27. Row 5 / Column 8 → 4 (Naked Single)
  28. Row 5 / Column 4 → 7 (Hidden Single)
  29. Row 9 / Column 6 → 7 (Hidden Single)
  30. Finned X-Wing: 8 c16 r24 fr3c6 => r2c4<>8
  31. AIC: 4/8 8- r2c1 -4- r2c2 =4= r8c2 =2= r8c8 -2- r7c7 -7- r7c9 =7= r1c9 =4= r1c3 -4- r4c3 =4= r4c1 -4 => r2c1<>4, r4c1<>8
  32. Row 2 / Column 1 → 8 (Naked Single)
  33. Discontinuous Nice Loop: 1 r3c6 -1- r3c9 -5- r4c9 -9- r4c8 =9= r9c8 =5= r9c4 =8= r4c4 -8- r4c6 =8= r3c6 => r3c6<>1
  34. Discontinuous Nice Loop: 3 r3c6 -3- r3c8 =3= r4c8 =9= r9c8 =5= r9c4 =8= r4c4 -8- r4c6 =8= r3c6 => r3c6<>3
  35. Discontinuous Nice Loop: 5 r3c6 -5- r3c7 =5= r6c7 -5- r4c9 -9- r4c8 =9= r9c8 =5= r9c4 =8= r4c4 -8- r4c6 =8= r3c6 => r3c6<>5
  36. Locked Candidates Type 1 (Pointing): 5 in b2 => r2c89<>5
  37. AIC: 6 6- r2c8 -2- r8c8 =2= r8c2 =4= r2c2 =6= r3c2 -6 => r2c2,r3c78<>6
  38. Row 3 / Column 2 → 6 (Hidden Single)
  39. Row 4 / Column 7 → 6 (Hidden Single)
  40. Locked Candidates Type 1 (Pointing): 9 in b1 => r7c3<>9
  41. Naked Pair: 2,4 in r28c2 => r7c2<>2
  42. XY-Chain: 1 1- r3c9 -5- r4c9 -9- r4c8 -3- r4c5 -1 => r3c5<>1
  43. Row 3 / Column 9 → 1 (Hidden Single)
  44. Row 4 / Column 5 → 1 (Hidden Single)
  45. Naked Triple: 2,4,6 in r2c289 => r2c46<>2
  46. X-Wing: 2 r28 c28 => r3c8<>2
  47. Naked Triple: 3,5,9 in r349c8 => r8c8<>5
  48. Jellyfish: 5 r2369 c4678 => r8c46<>5
  49. Locked Pair: 1,3 in r8c46 => r7c5,r8c1<>3
  50. Row 7 / Column 1 → 3 (Hidden Single)
  51. Row 3 / Column 5 → 3 (Hidden Single)
  52. Row 3 / Column 8 → 5 (Naked Single)
  53. Row 3 / Column 7 → 2 (Naked Single)
  54. Row 9 / Column 8 → 9 (Naked Single)
  55. Row 2 / Column 8 → 6 (Naked Single)
  56. Row 3 / Column 3 → 9 (Naked Single)
  57. Row 3 / Column 6 → 8 (Full House)
  58. Row 7 / Column 7 → 7 (Naked Single)
  59. Row 4 / Column 8 → 3 (Naked Single)
  60. Row 8 / Column 8 → 2 (Full House)
  61. Row 9 / Column 2 → 8 (Naked Single)
  62. Row 9 / Column 4 → 5 (Full House)
  63. Row 2 / Column 9 → 4 (Naked Single)
  64. Row 1 / Column 7 → 3 (Naked Single)
  65. Row 6 / Column 7 → 5 (Full House)
  66. Row 1 / Column 9 → 7 (Full House)
  67. Row 4 / Column 9 → 9 (Full House)
  68. Row 7 / Column 9 → 5 (Naked Single)
  69. Row 8 / Column 9 → 6 (Full House)
  70. Row 4 / Column 6 → 2 (Naked Single)
  71. Row 8 / Column 2 → 4 (Naked Single)
  72. Row 7 / Column 2 → 9 (Naked Single)
  73. Row 2 / Column 2 → 2 (Full House)
  74. Row 1 / Column 3 → 4 (Full House)
  75. Row 2 / Column 4 → 1 (Naked Single)
  76. Row 2 / Column 6 → 5 (Full House)
  77. Row 7 / Column 5 → 8 (Naked Single)
  78. Row 7 / Column 3 → 2 (Full House)
  79. Row 8 / Column 1 → 5 (Full House)
  80. Row 5 / Column 5 → 5 (Full House)
  81. Row 4 / Column 1 → 4 (Full House)
  82. Row 5 / Column 3 → 8 (Full House)
  83. Row 4 / Column 3 → 5 (Full House)
  84. Row 4 / Column 4 → 8 (Full House)
  85. Row 1 / Column 6 → 9 (Naked Single)
  86. Row 1 / Column 4 → 2 (Full House)
  87. Row 8 / Column 4 → 3 (Naked Single)
  88. Row 6 / Column 4 → 9 (Full House)
  89. Row 6 / Column 6 → 3 (Full House)
  90. Row 8 / Column 6 → 1 (Full House)
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