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

This Sudoku Puzzle has 87 steps and it is solved using Naked Single, Hidden Single, Locked Triple, Locked Candidates Type 1 (Pointing), Naked Pair, undefined, Naked Triple, AIC, Full House, Skyscraper, Discontinuous Nice Loop, Locked Candidates Type 2 (Claiming), Sue de Coq techniques.

Naked Single Explanation
Hidden Single Explanation
Locked Candidates Explanation
Locked Candidates Explanation
Full House Explanation
Try To Solve This Puzzle

Solution Steps:

  1. Row 9 / Column 6 → 7 (Naked Single)
  2. Row 8 / Column 6 → 8 (Naked Single)
  3. Row 2 / Column 6 → 4 (Hidden Single)
  4. Row 6 / Column 6 → 3 (Hidden Single)
  5. Locked Triple: 3,4,9 in r789c1 => r1c1,r78c3<>9, r4c1,r78c3<>3, r46c1,r7c3<>4
  6. Locked Candidates Type 1 (Pointing): 5 in b4 => r4c9<>5
  7. Locked Candidates Type 1 (Pointing): 7 in b7 => r456c3<>7
  8. Naked Pair: 4,9 in r9c17 => r9c4<>9
  9. 2-String Kite: 2 in r1c1,r5c4 (connected by r5c3,r6c1) => r1c4<>2
  10. X-Chain: 2 r5c4 =2= r5c3 -2- r6c1 =2= r1c1 -2- r1c6 =2= r7c6 => r7c4<>2
  11. Naked Triple: 1,6,9 in r79c4,r8c5 => r7c5<>6, r7c5<>9
  12. Row 1 / Column 5 → 6 (Hidden Single)
  13. XY-Chain: 7 7- r4c5 -1- r8c5 -9- r7c4 -6- r9c4 -1- r9c2 -6- r6c2 -7 => r4c2,r6c5<>7
  14. Row 6 / Column 2 → 7 (Hidden Single)
  15. AIC: 7 7- r5c8 -8- r5c4 =8= r4c4 =1= r9c4 -1- r9c2 =1= r8c3 =7= r8c9 -7 => r45c9,r7c8<>7
  16. Naked Pair: 4,9 in r7c8,r9c7 => r7c7<>4, r7c7,r8c9<>9
  17. XY-Chain: 7 7- r1c4 -9- r7c4 -6- r7c3 -7- r7c7 -3- r8c9 -7 => r1c9<>7
  18. AIC: 7 7- r1c4 =7= r1c7 =1= r1c3 -1- r8c3 -7- r8c9 =7= r3c9 -7 => r1c7,r3c45<>7
  19. Row 1 / Column 4 → 7 (Hidden Single)
  20. Row 4 / Column 5 → 7 (Hidden Single)
  21. XY-Wing: 1/2/8 in r4c4,r6c15 => r4c13<>8
  22. Row 4 / Column 1 → 5 (Naked Single)
  23. Naked Triple: 3,4,6 in r4c239 => r4c8<>4, r4c8<>6
  24. XY-Chain: 5 5- r3c2 -3- r4c2 -6- r9c2 -1- r9c4 -6- r7c4 -9- r8c5 -1- r6c5 -2- r7c5 -5 => r3c5<>5
  25. Row 7 / Column 5 → 5 (Hidden Single)
  26. Row 7 / Column 6 → 2 (Naked Single)
  27. Row 1 / Column 6 → 5 (Full House)
  28. Skyscraper: 2 in r1c1,r3c5 (connected by r6c15) => r3c3<>2
  29. XY-Chain: 5 5- r3c2 -3- r4c2 -6- r9c2 -1- r8c3 -7- r8c9 -3- r5c9 -5 => r3c9<>5
  30. XY-Chain: 3 3- r4c2 -6- r9c2 -1- r8c3 -7- r8c9 -3 => r4c9<>3
  31. Locked Candidates Type 1 (Pointing): 3 in b6 => r5c3<>3
  32. Naked Pair: 2,8 in r5c3,r6c1 => r6c3<>2, r6c3<>8
  33. Naked Pair: 2,8 in r5c34 => r5c78<>8
  34. Row 5 / Column 8 → 7 (Naked Single)
  35. Discontinuous Nice Loop: 9 r1c7 -9- r9c7 =9= r9c1 -9- r8c1 =9= r8c5 =1= r8c3 -1- r1c3 =1= r1c7 => r1c7<>9
  36. Discontinuous Nice Loop: 9 r2c8 -9- r1c9 -2- r1c1 =2= r6c1 -2- r6c5 -1- r8c5 -9- r8c1 -3- r8c9 =3= r5c9 =5= r2c9 =6= r2c8 => r2c8<>9
  37. Discontinuous Nice Loop: 9 r2c9 -9- r1c9 -2- r1c1 =2= r6c1 -2- r6c5 -1- r8c5 -9- r8c1 -3- r8c9 =3= r5c9 =5= r2c9 => r2c9<>9
  38. Discontinuous Nice Loop: 2 r3c9 -2- r3c5 -9- r8c5 -1- r8c3 -7- r8c9 =7= r3c9 => r3c9<>2
  39. Locked Candidates Type 2 (Claiming): 2 in r3 => r2c4<>2
  40. XY-Chain: 3 3- r2c4 -9- r7c4 -6- r9c4 -1- r9c2 -6- r4c2 -3 => r2c2<>3
  41. Sue de Coq: r2c789 - {12569} (r2c2 - {15}, r1c9 - {29}) => r3c789<>9, r2c3<>1
  42. XY-Chain: 1 1- r1c7 -8- r3c8 -4- r7c8 -9- r7c4 -6- r9c4 -1- r9c2 -6- r4c2 -3- r3c2 -5- r2c2 -1 => r1c3,r2c78<>1
  43. Row 2 / Column 8 → 6 (Naked Single)
  44. Row 1 / Column 7 → 1 (Hidden Single)
  45. Row 8 / Column 3 → 1 (Hidden Single)
  46. Row 8 / Column 5 → 9 (Naked Single)
  47. Row 9 / Column 2 → 6 (Naked Single)
  48. Row 3 / Column 5 → 2 (Naked Single)
  49. Row 6 / Column 5 → 1 (Full House)
  50. Row 7 / Column 4 → 6 (Naked Single)
  51. Row 9 / Column 4 → 1 (Full House)
  52. Row 8 / Column 1 → 3 (Naked Single)
  53. Row 8 / Column 9 → 7 (Full House)
  54. Row 4 / Column 2 → 3 (Naked Single)
  55. Row 7 / Column 3 → 7 (Naked Single)
  56. Row 4 / Column 4 → 8 (Naked Single)
  57. Row 5 / Column 4 → 2 (Full House)
  58. Row 3 / Column 9 → 4 (Naked Single)
  59. Row 7 / Column 7 → 3 (Naked Single)
  60. Row 3 / Column 2 → 5 (Naked Single)
  61. Row 2 / Column 2 → 1 (Full House)
  62. Row 4 / Column 8 → 1 (Naked Single)
  63. Row 5 / Column 3 → 8 (Naked Single)
  64. Row 3 / Column 8 → 8 (Naked Single)
  65. Row 4 / Column 9 → 6 (Naked Single)
  66. Row 4 / Column 3 → 4 (Full House)
  67. Row 5 / Column 7 → 5 (Naked Single)
  68. Row 5 / Column 9 → 3 (Full House)
  69. Row 6 / Column 1 → 2 (Naked Single)
  70. Row 6 / Column 3 → 6 (Full House)
  71. Row 3 / Column 7 → 7 (Naked Single)
  72. Row 6 / Column 9 → 9 (Naked Single)
  73. Row 2 / Column 7 → 9 (Naked Single)
  74. Row 1 / Column 1 → 8 (Naked Single)
  75. Row 1 / Column 9 → 2 (Naked Single)
  76. Row 1 / Column 3 → 9 (Full House)
  77. Row 2 / Column 9 → 5 (Full House)
  78. Row 6 / Column 8 → 4 (Naked Single)
  79. Row 6 / Column 7 → 8 (Full House)
  80. Row 9 / Column 7 → 4 (Full House)
  81. Row 7 / Column 8 → 9 (Full House)
  82. Row 9 / Column 1 → 9 (Full House)
  83. Row 7 / Column 1 → 4 (Full House)
  84. Row 2 / Column 4 → 3 (Naked Single)
  85. Row 2 / Column 3 → 2 (Full House)
  86. Row 3 / Column 3 → 3 (Full House)
  87. Row 3 / Column 4 → 9 (Full House)
Show More...