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

This Sudoku Puzzle has 69 steps and it is solved using Hidden Single, Full House, Naked Single, Locked Candidates Type 2 (Claiming), Naked Triple, Skyscraper, Empty Rectangle, Uniqueness Test 4, undefined, Swordfish, Naked Pair techniques.

Try To Solve This Puzzle

## Solution Steps:

1. Row 5 / Column 9 → 4 (Hidden Single)
2. Row 5 / Column 7 → 6 (Hidden Single)
3. Row 8 / Column 4 → 4 (Hidden Single)
4. Row 7 / Column 9 → 1 (Hidden Single)
5. Row 6 / Column 7 → 1 (Hidden Single)
6. Row 7 / Column 3 → 4 (Hidden Single)
7. Row 3 / Column 2 → 4 (Hidden Single)
8. Row 6 / Column 8 → 3 (Hidden Single)
9. Row 4 / Column 8 → 2 (Full House)
10. Row 1 / Column 6 → 4 (Hidden Single)
11. Row 2 / Column 5 → 3 (Hidden Single)
12. Row 8 / Column 3 → 3 (Hidden Single)
13. Row 4 / Column 1 → 3 (Hidden Single)
14. Row 8 / Column 2 → 1 (Hidden Single)
15. Row 4 / Column 2 → 5 (Naked Single)
16. Row 4 / Column 3 → 9 (Hidden Single)
17. Row 4 / Column 4 → 6 (Naked Single)
18. Row 4 / Column 6 → 1 (Full House)
19. Row 6 / Column 4 → 9 (Hidden Single)
20. Row 3 / Column 5 → 1 (Hidden Single)
21. Locked Candidates Type 2 (Claiming): 2 in r8 => r7c56,r9c56<>2
22. Naked Triple: 2,5,7 in r1c379 => r1c15<>2, r1c1<>7, r1c5<>5
23. Skyscraper: 2 in r5c4,r6c2 (connected by r2c24) => r5c13,r6c6<>2
24. Row 6 / Column 6 → 7 (Naked Single)
25. Row 6 / Column 2 → 2 (Full House)
26. Row 2 / Column 2 → 7 (Full House)
27. Row 1 / Column 9 → 7 (Hidden Single)
28. Skyscraper: 2 in r1c3,r7c1 (connected by r17c7) => r23c1,r9c3<>2
29. Empty Rectangle: 5 in b2 (r27c8) => r7c6<>5
30. Uniqueness Test 4: 2/3 in r3c79,r9c79 => r39c7<>2
31. XY-Chain: 5 5- r2c4 -2- r5c4 -5- r5c5 -2- r8c5 -7- r8c8 -8- r2c8 -5 => r2c36<>5
32. XY-Chain: 9 9- r1c5 -6- r2c6 -2- r8c6 -8- r7c6 -9 => r3c6,r7c5<>9
33. Row 3 / Column 1 → 9 (Hidden Single)
34. Row 1 / Column 1 → 6 (Naked Single)
35. Row 1 / Column 5 → 9 (Naked Single)
36. Row 7 / Column 6 → 9 (Hidden Single)
37. Row 9 / Column 5 → 6 (Hidden Single)
38. Row 2 / Column 6 → 6 (Hidden Single)
39. Locked Candidates Type 2 (Claiming): 7 in r9 => r7c1<>7
40. Swordfish: 5 r139 c367 => r7c7<>5
41. Naked Pair: 2,8 in r7c17 => r7c8<>8
42. Skyscraper: 8 in r3c3,r7c1 (connected by r37c7) => r2c1,r9c3<>8
43. Row 2 / Column 1 → 1 (Naked Single)
44. Row 9 / Column 3 → 7 (Naked Single)
45. Row 5 / Column 1 → 7 (Naked Single)
46. Row 5 / Column 3 → 1 (Full House)
47. W-Wing: 5/2 in r1c3,r3c6 connected by 2 in r2c34 => r3c3<>5
48. Row 1 / Column 3 → 5 (Hidden Single)
49. Row 1 / Column 7 → 2 (Full House)
50. Row 3 / Column 9 → 3 (Naked Single)
51. Row 9 / Column 9 → 2 (Full House)
52. Row 7 / Column 7 → 8 (Naked Single)
53. Row 9 / Column 1 → 8 (Naked Single)
54. Row 7 / Column 1 → 2 (Full House)
55. Row 3 / Column 7 → 5 (Naked Single)
56. Row 2 / Column 8 → 8 (Full House)
57. Row 9 / Column 7 → 3 (Full House)
58. Row 9 / Column 6 → 5 (Full House)
59. Row 8 / Column 8 → 7 (Naked Single)
60. Row 7 / Column 8 → 5 (Full House)
61. Row 7 / Column 5 → 7 (Full House)
62. Row 3 / Column 6 → 2 (Naked Single)
63. Row 2 / Column 4 → 5 (Full House)
64. Row 2 / Column 3 → 2 (Full House)
65. Row 3 / Column 3 → 8 (Full House)
66. Row 8 / Column 6 → 8 (Full House)
67. Row 8 / Column 5 → 2 (Full House)
68. Row 5 / Column 4 → 2 (Full House)
69. Row 5 / Column 5 → 5 (Full House)