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

This Sudoku Puzzle has 47 steps and it is solved using Naked Single, Full House, Hidden Single, Locked Pair, Locked Candidates Type 1 (Pointing), Uniqueness Test 1, Hidden Rectangle, AIC, Naked Triple, Hidden Pair, Uniqueness Test 4, Empty Rectangle, Uniqueness Test 6, Sue de Coq, Discontinuous Nice Loop, Give Up techniques.

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

Solution Steps:

  1. Row 2 / Column 3 → 4 (Naked Single)
  2. Row 2 / Column 2 → 9 (Full House)
  3. Row 1 / Column 4 → 8 (Hidden Single)
  4. Row 5 / Column 4 → 4 (Hidden Single)
  5. Row 4 / Column 1 → 9 (Hidden Single)
  6. Row 1 / Column 5 → 6 (Hidden Single)
  7. Row 3 / Column 8 → 6 (Hidden Single)
  8. Row 1 / Column 7 → 9 (Hidden Single)
  9. Row 8 / Column 9 → 4 (Hidden Single)
  10. Row 1 / Column 9 → 3 (Naked Single)
  11. Row 1 / Column 8 → 4 (Full House)
  12. Locked Pair: 2,8 in r8c13 => r8c46,r9c3<>2, r8c6,r9c3<>8
  13. Locked Candidates Type 1 (Pointing): 1 in b3 => r56c7<>1
  14. Locked Candidates Type 1 (Pointing): 2 in b3 => r57c7<>2
  15. Uniqueness Test 1: 1/2 in r2c47,r3c47 => r2c4<>1, r2c4<>2
  16. Uniqueness Test 1: 2/8 in r5c13,r8c13 => r5c3<>2, r5c3<>8
  17. Hidden Rectangle: 1/4 in r7c25,r9c25 => r9c5<>1
  18. AIC: 1 1- r2c5 -3- r2c4 =3= r9c4 =2= r3c4 =1= r3c7 -1 => r2c7,r3c4<>1
  19. Row 2 / Column 7 → 2 (Naked Single)
  20. Row 3 / Column 7 → 1 (Full House)
  21. Row 3 / Column 4 → 2 (Full House)
  22. Naked Triple: 1,3,4 in r79c5,r9c4 => r79c6<>1
  23. Hidden Pair: 1,4 in r7c25 => r7c5<>3
  24. Locked Candidates Type 1 (Pointing): 3 in b8 => r9c8<>3
  25. Uniqueness Test 1: 2/8 in r7c68,r9c68 => r7c8<>2, r7c8<>8
  26. Row 7 / Column 8 → 3 (Naked Single)
  27. Uniqueness Test 4: 1/4 in r7c25,r9c25 => r9c2<>1
  28. Empty Rectangle: 1 in b5 (r9c34) => r6c3<>1
  29. Uniqueness Test 6: 1/3 in r2c45,r9c45 => r2c4,r9c5<>3
  30. Row 2 / Column 4 → 5 (Naked Single)
  31. Row 9 / Column 5 → 4 (Naked Single)
  32. Row 2 / Column 6 → 1 (Naked Single)
  33. Row 2 / Column 5 → 3 (Full House)
  34. Row 7 / Column 5 → 1 (Full House)
  35. Row 8 / Column 4 → 9 (Naked Single)
  36. Row 9 / Column 2 → 6 (Naked Single)
  37. Row 6 / Column 6 → 9 (Naked Single)
  38. Row 7 / Column 2 → 4 (Naked Single)
  39. Row 9 / Column 4 → 3 (Naked Single)
  40. Row 8 / Column 6 → 5 (Naked Single)
  41. Row 9 / Column 3 → 1 (Naked Single)
  42. Row 5 / Column 3 → 3 (Naked Single)
  43. Row 6 / Column 7 → 3 (Hidden Single)
  44. Sue de Coq: r5c79 - {1278} (r5c2 - {17}, r46c8 - {258}) => r4c9<>2
  45. Discontinuous Nice Loop: 1 r4c2 -1- r5c2 =1= r5c9 =2= r4c8 =5= r4c2 => r4c2<>1
  46. Discontinuous Nice Loop: 7 r6c9 -7- r6c4 -1- r4c4 =1= r4c9 =6= r6c9 => r6c9<>7
  47. Give Up: Don't know how to proceed!
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