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

This Sudoku Puzzle has 77 steps and it is solved using Naked Single, Hidden Single, Locked Pair, Locked Candidates Type 1 (Pointing), Locked Candidates Type 2 (Claiming), Naked Pair, Uniqueness Test 2, Full House, Discontinuous Nice Loop, Grouped Discontinuous Nice Loop, Uniqueness Test 3, undefined, AIC, Hidden Pair, Bivalue Universal Grave + 1 techniques.

Try To Solve This Puzzle

## Solution Steps:

1. Row 6 / Column 2 → 8 (Naked Single)
2. Row 4 / Column 2 → 4 (Hidden Single)
3. Row 5 / Column 9 → 9 (Hidden Single)
4. Row 6 / Column 4 → 9 (Hidden Single)
5. Row 3 / Column 5 → 9 (Hidden Single)
6. Row 5 / Column 7 → 2 (Hidden Single)
7. Row 2 / Column 2 → 9 (Hidden Single)
8. Row 6 / Column 6 → 2 (Hidden Single)
9. Row 7 / Column 1 → 9 (Hidden Single)
10. Row 5 / Column 8 → 8 (Hidden Single)
11. Row 2 / Column 8 → 3 (Hidden Single)
12. Row 5 / Column 5 → 7 (Hidden Single)
13. Row 4 / Column 8 → 1 (Hidden Single)
14. Row 4 / Column 9 → 7 (Hidden Single)
15. Row 4 / Column 7 → 3 (Hidden Single)
16. Locked Pair: 5,6 in r13c9 => r13c7,r7c9<>5, r13c7,r79c9<>6
17. Locked Candidates Type 1 (Pointing): 4 in b3 => r79c7<>4
18. Locked Candidates Type 2 (Claiming): 6 in r2 => r1c456,r3c6<>6
19. Locked Candidates Type 2 (Claiming): 6 in c5 => r7c6,r9c4<>6
20. Naked Pair: 1,5 in r25c3 => r1379c3<>1, r13c3<>5
21. Uniqueness Test 2: 5/6 in r2c46,r4c46 => r1c46,r2c3,r3c6<>1
22. Row 2 / Column 3 → 5 (Naked Single)
23. Row 5 / Column 3 → 1 (Naked Single)
24. Row 5 / Column 1 → 5 (Full House)
25. Discontinuous Nice Loop: 5 r1c6 -5- r4c6 -6- r2c6 -1- r7c6 =1= r7c2 -1- r3c2 -7- r3c6 =7= r1c6 => r1c6<>5
26. Discontinuous Nice Loop: 8 r3c1 -8- r3c3 -7- r3c2 -1- r7c2 =1= r7c6 -1- r2c6 -6- r4c6 -5- r3c6 =5= r3c9 =6= r3c1 => r3c1<>8
27. Discontinuous Nice Loop: 4 r7c6 -4- r7c3 =4= r9c3 =7= r8c2 -7- r3c2 -1- r7c2 =1= r7c6 => r7c6<>4
28. Grouped Discontinuous Nice Loop: 5 r7c6 -5- r7c78 =5= r8c8 =7= r8c2 -7- r3c2 -1- r7c2 =1= r7c6 => r7c6<>5
29. Uniqueness Test 3: 5/6 in r6c78,r7c78 => r7c5<>3, r7c5<>4
30. W-Wing: 6/5 in r6c8,r7c5 connected by 5 in r67c7 => r7c8<>6
31. AIC: 5/6 6- r6c8 =6= r9c8 =7= r9c3 =4= r7c3 -4- r7c8 -5- r7c7 =5= r6c7 -5 => r6c8<>5, r6c7<>6
32. Row 6 / Column 8 → 6 (Naked Single)
33. Row 6 / Column 7 → 5 (Full House)
34. XY-Chain: 5 5- r4c6 -6- r2c6 -1- r7c6 -8- r7c7 -6- r7c5 -5 => r8c6<>5
35. AIC: 1 1- r3c2 -7- r8c2 =7= r8c8 =5= r7c8 -5- r7c5 -6- r7c7 -8- r7c6 -1- r7c2 =1= r9c1 -1 => r13c1,r7c2<>1
36. Row 3 / Column 1 → 6 (Naked Single)
37. Row 3 / Column 9 → 5 (Naked Single)
38. Row 1 / Column 9 → 6 (Naked Single)
39. Row 9 / Column 1 → 1 (Hidden Single)
40. Row 7 / Column 6 → 1 (Hidden Single)
41. Row 2 / Column 6 → 6 (Naked Single)
42. Row 2 / Column 4 → 1 (Full House)
43. Row 4 / Column 6 → 5 (Naked Single)
44. Row 4 / Column 4 → 6 (Full House)
45. Naked Pair: 2,3 in r7c29 => r7c3<>2
46. 2-String Kite: 8 in r3c6,r8c1 (connected by r1c1,r3c3) => r8c6<>8
47. Row 8 / Column 6 → 4 (Naked Single)
48. Row 3 / Column 7 → 4 (Hidden Single)
49. Row 1 / Column 7 → 1 (Full House)
50. Row 1 / Column 5 → 4 (Hidden Single)
51. Row 3 / Column 2 → 1 (Hidden Single)
52. Row 1 / Column 4 → 5 (Hidden Single)
53. Hidden Pair: 4,7 in r9c38 => r9c3<>2, r9c3<>8
54. Row 1 / Column 3 → 2 (Hidden Single)
55. Bivalue Universal Grave + 1 => r8c2<>2, r8c2<>7
56. Row 8 / Column 2 → 3 (Naked Single)
57. Row 1 / Column 2 → 7 (Naked Single)
58. Row 7 / Column 2 → 2 (Full House)
59. Row 8 / Column 1 → 8 (Naked Single)
60. Row 1 / Column 1 → 3 (Full House)
61. Row 1 / Column 6 → 8 (Full House)
62. Row 3 / Column 3 → 8 (Full House)
63. Row 3 / Column 6 → 7 (Full House)
64. Row 8 / Column 5 → 5 (Naked Single)
65. Row 7 / Column 9 → 3 (Naked Single)
66. Row 9 / Column 9 → 2 (Full House)
67. Row 7 / Column 3 → 4 (Naked Single)
68. Row 9 / Column 3 → 7 (Full House)
69. Row 8 / Column 4 → 2 (Naked Single)
70. Row 8 / Column 8 → 7 (Full House)
71. Row 9 / Column 4 → 8 (Full House)
72. Row 7 / Column 5 → 6 (Naked Single)
73. Row 9 / Column 5 → 3 (Full House)
74. Row 7 / Column 8 → 5 (Naked Single)
75. Row 9 / Column 8 → 4 (Full House)
76. Row 9 / Column 7 → 6 (Full House)
77. Row 7 / Column 7 → 8 (Full House)