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.

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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