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

This Sudoku Puzzle has 41 steps and it is solved using Hidden Single, Locked Candidates Type 1 (Pointing), Naked Triple, Naked Pair, Locked Candidates Type 2 (Claiming), Empty Rectangle, Naked Single, Uniqueness Test 4, undefined, Discontinuous Nice Loop, Hidden Triple, Uniqueness Test 1, Jellyfish, Turbot Fish, Give Up techniques.

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

Solution Steps:

  1. Row 1 / Column 4 → 8 (Hidden Single)
  2. Row 1 / Column 5 → 6 (Hidden Single)
  3. Row 3 / Column 8 → 6 (Hidden Single)
  4. Row 7 / Column 9 → 7 (Hidden Single)
  5. Locked Candidates Type 1 (Pointing): 4 in b1 => r2c7<>4
  6. Locked Candidates Type 1 (Pointing): 3 in b2 => r2c7<>3
  7. Locked Candidates Type 1 (Pointing): 2 in b3 => r47c7<>2
  8. Locked Candidates Type 1 (Pointing): 8 in b6 => r6c3<>8
  9. Naked Triple: 1,4,5 in r5c245 => r5c139<>1, r5c9<>4
  10. Locked Candidates Type 1 (Pointing): 4 in b6 => r4c4<>4
  11. Naked Pair: 2,8 in r58c1 => r4c1<>2
  12. Naked Triple: 2,4,8 in r8c139 => r8c46<>2, r8c4<>4, r8c6<>8
  13. Locked Candidates Type 2 (Claiming): 8 in r8 => r9c3<>8
  14. Empty Rectangle: 1 in b3 (r14c1) => r4c7<>1
  15. Row 4 / Column 7 → 4 (Naked Single)
  16. Uniqueness Test 4: 2/8 in r5c13,r8c13 => r58c3<>2
  17. X-Wing: 2 r58 c19 => r4c9<>2
  18. XY-Chain: 5 5- r4c8 -2- r5c9 -3- r5c3 -8- r8c3 -4- r7c2 -1- r5c2 -5 => r4c2<>5
  19. Discontinuous Nice Loop: 1 r4c3 -1- r2c3 -4- r8c3 -8- r8c1 -2- r5c1 =2= r4c3 => r4c3<>1
  20. XY-Chain: 2 2- r4c3 -6- r4c9 -1- r4c1 -9- r1c1 -1- r2c3 -4- r8c3 -8- r5c3 -3- r5c9 -2 => r4c8,r5c1<>2
  21. Row 4 / Column 8 → 5 (Naked Single)
  22. Row 5 / Column 1 → 8 (Naked Single)
  23. Row 5 / Column 3 → 3 (Naked Single)
  24. Row 8 / Column 1 → 2 (Naked Single)
  25. Row 5 / Column 9 → 2 (Naked Single)
  26. Row 8 / Column 9 → 4 (Naked Single)
  27. Row 8 / Column 3 → 8 (Naked Single)
  28. Row 4 / Column 3 → 2 (Hidden Single)
  29. Row 1 / Column 8 → 4 (Hidden Single)
  30. Hidden Triple: 5,7,9 in r6c246 => r6c246<>1, r6c2<>6
  31. Naked Pair: 5,9 in r68c6 => r2c6<>5
  32. Naked Pair: 1,2 in r2c6,r3c4 => r2c45<>1, r2c4<>2
  33. Uniqueness Test 1: 5/9 in r6c46,r8c46 => r6c4<>5, r6c4<>9
  34. Row 6 / Column 4 → 7 (Naked Single)
  35. Row 4 / Column 2 → 7 (Hidden Single)
  36. Row 4 / Column 9 → 6 (Hidden Single)
  37. Row 9 / Column 2 → 6 (Hidden Single)
  38. Row 6 / Column 3 → 6 (Hidden Single)
  39. Jellyfish: 1 r1346 c1479 => r2c7,r59c4<>1
  40. Turbot Fish: 1 r5c5 =1= r5c2 -1- r7c2 =1= r9c3 => r9c5<>1
  41. Give Up: Don't know how to proceed!
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