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

This Sudoku Puzzle has 69 steps and it is solved using Hidden Single, Locked Candidates Type 1 (Pointing), Locked Candidates Type 2 (Claiming), Swordfish, Skyscraper, undefined, Uniqueness Test 2, Naked Single, Full House techniques.

Try To Solve This Puzzle

## Solution Steps:

1. Row 2 / Column 1 → 4 (Hidden Single)
2. Row 5 / Column 8 → 4 (Hidden Single)
3. Row 7 / Column 6 → 2 (Hidden Single)
4. Row 3 / Column 9 → 8 (Hidden Single)
5. Row 9 / Column 9 → 2 (Hidden Single)
6. Row 9 / Column 2 → 4 (Hidden Single)
7. Row 2 / Column 3 → 8 (Hidden Single)
8. Row 3 / Column 4 → 4 (Hidden Single)
9. Row 1 / Column 9 → 4 (Hidden Single)
10. Row 2 / Column 7 → 6 (Hidden Single)
11. Locked Candidates Type 1 (Pointing): 7 in b3 => r3c5<>7
12. Locked Candidates Type 2 (Claiming): 5 in r2 => r1c46,r3c5<>5
13. Swordfish: 3 r157 c347 => r38c3,r4c4<>3
14. Skyscraper: 8 in r6c1,r7c2 (connected by r67c4) => r5c2,r8c1<>8
15. Row 7 / Column 2 → 8 (Hidden Single)
16. Row 6 / Column 1 → 8 (Hidden Single)
17. Row 8 / Column 6 → 8 (Hidden Single)
18. Row 5 / Column 4 → 8 (Hidden Single)
19. Row 5 / Column 7 → 3 (Hidden Single)
20. Row 1 / Column 4 → 3 (Hidden Single)
21. Row 4 / Column 5 → 3 (Hidden Single)
22. Row 8 / Column 9 → 3 (Hidden Single)
23. Row 7 / Column 3 → 3 (Hidden Single)
24. Row 3 / Column 1 → 3 (Hidden Single)
25. Row 9 / Column 3 → 9 (Hidden Single)
26. Row 3 / Column 3 → 2 (Hidden Single)
27. Row 4 / Column 1 → 2 (Hidden Single)
28. Row 8 / Column 3 → 7 (Hidden Single)
29. Row 6 / Column 8 → 2 (Hidden Single)
30. Locked Candidates Type 2 (Claiming): 5 in c9 => r4c8,r6c7<>5
31. Locked Candidates Type 2 (Claiming): 7 in c9 => r4c8,r6c7<>7
32. W-Wing: 7/5 in r2c5,r9c7 connected by 5 in r8c58 => r9c5<>7
33. Locked Candidates Type 1 (Pointing): 7 in b8 => r46c4<>7
34. W-Wing: 1/9 in r3c5,r4c8 connected by 9 in r6c57 => r3c8<>1
35. Uniqueness Test 2: 1/6 in r8c15,r9c15 => r26c5,r9c4<>5
36. Row 2 / Column 5 → 7 (Naked Single)
37. Row 2 / Column 6 → 5 (Full House)
38. Row 6 / Column 9 → 7 (Hidden Single)
39. Row 4 / Column 9 → 5 (Full House)
40. Row 6 / Column 4 → 5 (Hidden Single)
41. W-Wing: 6/1 in r4c4,r6c3 connected by 1 in r5c36 => r4c2,r6c5<>6
42. Row 4 / Column 2 → 7 (Naked Single)
43. Row 5 / Column 2 → 5 (Naked Single)
44. Row 3 / Column 2 → 9 (Naked Single)
45. Row 1 / Column 2 → 6 (Full House)
46. Row 1 / Column 3 → 5 (Full House)
47. Row 5 / Column 3 → 1 (Naked Single)
48. Row 5 / Column 6 → 7 (Full House)
49. Row 6 / Column 3 → 6 (Full House)
50. Row 3 / Column 5 → 1 (Naked Single)
51. Row 1 / Column 6 → 9 (Full House)
52. Row 1 / Column 8 → 1 (Full House)
53. Row 4 / Column 6 → 1 (Full House)
54. Row 6 / Column 5 → 9 (Naked Single)
55. Row 4 / Column 4 → 6 (Full House)
56. Row 4 / Column 8 → 9 (Full House)
57. Row 6 / Column 7 → 1 (Full House)
58. Row 7 / Column 4 → 7 (Naked Single)
59. Row 9 / Column 4 → 1 (Full House)
60. Row 7 / Column 7 → 9 (Naked Single)
61. Row 7 / Column 8 → 6 (Full House)
62. Row 9 / Column 1 → 6 (Naked Single)
63. Row 8 / Column 1 → 1 (Full House)
64. Row 8 / Column 8 → 5 (Naked Single)
65. Row 3 / Column 8 → 7 (Full House)
66. Row 8 / Column 5 → 6 (Full House)
67. Row 9 / Column 5 → 5 (Full House)
68. Row 9 / Column 7 → 7 (Full House)
69. Row 3 / Column 7 → 5 (Full House)