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

This Sudoku Puzzle has 69 steps and it is solved using Hidden Single, Naked Single, Full House, Locked Candidates Type 1 (Pointing), Locked Candidates Type 2 (Claiming), Naked Pair, Empty Rectangle, Sue de Coq, Continuous Nice Loop, undefined 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 5 / Column 5 → 4 (Hidden Single)
  2. Row 1 / Column 1 → 2 (Hidden Single)
  3. Row 9 / Column 7 → 9 (Hidden Single)
  4. Row 5 / Column 3 → 9 (Hidden Single)
  5. Row 5 / Column 1 → 1 (Hidden Single)
  6. Row 4 / Column 3 → 6 (Hidden Single)
  7. Row 4 / Column 8 → 8 (Hidden Single)
  8. Row 3 / Column 3 → 8 (Hidden Single)
  9. Row 3 / Column 1 → 3 (Naked Single)
  10. Row 3 / Column 9 → 6 (Naked Single)
  11. Row 9 / Column 1 → 7 (Naked Single)
  12. Row 3 / Column 7 → 4 (Naked Single)
  13. Row 7 / Column 1 → 5 (Naked Single)
  14. Row 6 / Column 1 → 8 (Full House)
  15. Row 3 / Column 8 → 9 (Naked Single)
  16. Row 3 / Column 5 → 1 (Full House)
  17. Row 4 / Column 4 → 1 (Hidden Single)
  18. Row 8 / Column 4 → 7 (Hidden Single)
  19. Row 4 / Column 6 → 7 (Hidden Single)
  20. Locked Candidates Type 1 (Pointing): 3 in b4 => r8c2<>3
  21. Locked Candidates Type 1 (Pointing): 5 in b4 => r12c2<>5
  22. Locked Candidates Type 1 (Pointing): 6 in b5 => r6c8<>6
  23. Locked Candidates Type 2 (Claiming): 5 in r5 => r4c7<>5
  24. Naked Pair: 2,3 in r26c8 => r7c8<>2, r78c8<>3
  25. Empty Rectangle: 4 in b2 (r9c34) => r2c3<>4
  26. Sue de Coq: r78c7 - {2367} (r4c7 - {23}, r78c8 - {467}) => r7c9<>7, r1c7<>3
  27. Continuous Nice Loop: 4/5/6/7 6= r5c7 =5= r5c9 -5- r2c9 =5= r2c3 =1= r2c2 -1- r8c2 -4- r8c8 -6- r5c8 =6= r5c7 =5 => r8c6<>4, r1c9<>5, r7c8<>6, r5c7<>7
  28. XY-Chain: 5 5- r4c5 -2- r4c7 -3- r8c7 -6- r5c7 -5- r5c9 -7- r1c9 -3- r2c8 -2- r6c8 -3- r6c2 -5 => r4c2,r6c56<>5
  29. Row 4 / Column 2 → 3 (Naked Single)
  30. Row 6 / Column 2 → 5 (Full House)
  31. Row 4 / Column 7 → 2 (Naked Single)
  32. Row 4 / Column 5 → 5 (Full House)
  33. Row 6 / Column 8 → 3 (Naked Single)
  34. Row 2 / Column 8 → 2 (Naked Single)
  35. Row 8 / Column 6 → 5 (Hidden Single)
  36. Locked Candidates Type 1 (Pointing): 3 in b3 => r789c9<>3
  37. XY-Chain: 3 3- r1c9 -7- r1c7 -5- r5c7 -6- r5c8 -7- r7c8 -4- r7c6 -6- r6c6 -9- r2c6 -4- r2c4 -3 => r1c45,r2c9<>3
  38. Row 2 / Column 9 → 5 (Naked Single)
  39. Row 1 / Column 7 → 7 (Naked Single)
  40. Row 1 / Column 9 → 3 (Full House)
  41. Row 2 / Column 3 → 1 (Naked Single)
  42. Row 5 / Column 9 → 7 (Naked Single)
  43. Row 5 / Column 8 → 6 (Naked Single)
  44. Row 5 / Column 7 → 5 (Full House)
  45. Row 8 / Column 8 → 4 (Naked Single)
  46. Row 7 / Column 8 → 7 (Full House)
  47. Row 8 / Column 2 → 1 (Naked Single)
  48. Row 8 / Column 9 → 8 (Naked Single)
  49. Row 9 / Column 9 → 2 (Naked Single)
  50. Row 7 / Column 9 → 1 (Full House)
  51. Row 2 / Column 4 → 3 (Hidden Single)
  52. Row 9 / Column 4 → 4 (Naked Single)
  53. Row 1 / Column 4 → 6 (Naked Single)
  54. Row 6 / Column 4 → 2 (Full House)
  55. Row 7 / Column 6 → 6 (Naked Single)
  56. Row 9 / Column 3 → 3 (Naked Single)
  57. Row 7 / Column 3 → 4 (Full House)
  58. Row 9 / Column 5 → 8 (Full House)
  59. Row 1 / Column 3 → 5 (Full House)
  60. Row 1 / Column 5 → 9 (Naked Single)
  61. Row 1 / Column 2 → 4 (Full House)
  62. Row 2 / Column 6 → 4 (Full House)
  63. Row 6 / Column 6 → 9 (Full House)
  64. Row 6 / Column 5 → 6 (Full House)
  65. Row 2 / Column 2 → 9 (Full House)
  66. Row 7 / Column 7 → 3 (Naked Single)
  67. Row 7 / Column 5 → 2 (Full House)
  68. Row 8 / Column 5 → 3 (Full House)
  69. Row 8 / Column 7 → 6 (Full House)
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