Passaggi della soluzione:

1. Riga 4 / Colonna 8 → 6 (Hidden Single)
2. Riga 6 / Colonna 9 → 8 (Hidden Single)
3. Riga 3 / Colonna 4 → 6 (Hidden Single)
4. Riga 5 / Colonna 8 → 3 (Hidden Single)
5. Locked Pair: 4,7 in r13c1 => r1c23,r468c1<>7, r1c23,r78c1<>4
6. Locked Candidates Type 1 (Pointing): 1 in b1 => r1c457<>1
7. Locked Candidates Type 1 (Pointing): 1 in b3 => r5c9<>1
8. Riga 5 / Colonna 9 → 7 (Naked Single)
9. Locked Candidates Type 1 (Pointing): 5 in b5 => r13c6<>5
10. Locked Candidates Type 1 (Pointing): 7 in b5 => r12c4<>7
11. Locked Candidates Type 1 (Pointing): 2 in b6 => r1c7<>2
12. Locked Candidates Type 1 (Pointing): 4 in b8 => r12c4<>4
13. Hidden Rectangle: 5/7 in r1c58,r3c58 => r1c5<>7
14. AIC: 5 5- r4c1 -2- r8c1 =2= r8c5 -2- r5c5 -1- r3c5 =1= r3c9 =5= r7c9 -5- r9c8 =5= r9c3 -5 => r46c3,r7c1<>5
15. Hidden Rectangle: 2/5 in r4c16,r6c16 => r6c6<>2
16. Discontinuous Nice Loop: 4/7/9 r9c3 =5= r9c8 =8= r8c8 -8- r8c5 -2- r5c5 -1- r3c5 =1= r3c9 =5= r7c9 -5- r7c3 =5= r9c3 => r9c3<>4, r9c3<>7, r9c3<>9
17. Riga 9 / Colonna 3 → 5 (Naked Single)
18. Riga 7 / Colonna 9 → 5 (Hidden Single)
19. Riga 8 / Colonna 9 → 6 (Hidden Single)
20. Locked Candidates Type 1 (Pointing): 9 in b7 => r8c78<>9
21. Locked Candidates Type 1 (Pointing): 4 in b9 => r1c7<>4
22. Discontinuous Nice Loop: 2 r1c5 -2- r8c5 -8- r8c8 -7- r3c8 -5- r3c5 =5= r1c5 => r1c5<>2
23. Discontinuous Nice Loop: 9 r1c4 -9- r1c7 -7- r3c8 -5- r3c5 =5= r1c5 =8= r1c4 => r1c4<>9
24. Discontinuous Nice Loop: 1 r2c5 -1- r5c5 -2- r8c5 -8- r8c8 -7- r2c8 =7= r2c5 => r2c5<>1
25. XY-Wing: 2/8/7 in r28c5,r8c8 => r2c8<>7
26. Riga 2 / Colonna 5 → 7 (Hidden Single)
27. AIC: 1/9 1- r2c4 =1= r3c5 -1- r5c5 -2- r8c5 =2= r8c1 =9= r8c3 -9- r5c3 =9= r5c4 -9 => r5c4<>1, r2c4<>9
28. Locked Candidates Type 1 (Pointing): 9 in b2 => r6c6<>9
29. W-Wing: 1/2 in r2c4,r5c5 connected by 2 in r7c4,r8c5 => r3c5,r46c4<>1
30. Riga 3 / Colonna 9 → 1 (Hidden Single)
31. Riga 2 / Colonna 9 → 4 (Full House)
32. Riga 5 / Colonna 5 → 1 (Hidden Single)
33. Riga 2 / Colonna 4 → 1 (Hidden Single)
34. Riga 8 / Colonna 5 → 2 (Hidden Single)
35. Hidden Triple: 1,3,7 in r46c3,r6c2 => r6c2<>2, r6c3<>9
36. XYZ-Wing: 2/4/6 in r57c2,r7c3 => r9c2<>4
37. Riga 9 / Colonna 2 → 7 (Naked Single)
38. Riga 6 / Colonna 2 → 1 (Naked Single)
39. Riga 1 / Colonna 2 → 6 (Naked Single)
40. Riga 6 / Colonna 7 → 2 (Naked Single)
41. Riga 4 / Colonna 7 → 1 (Full House)
42. Riga 1 / Colonna 3 → 1 (Naked Single)
43. Riga 7 / Colonna 3 → 6 (Hidden Single)
44. Uniqueness Test 3: 3/7 in r4c34,r6c34 => r79c4<>8
45. Riga 7 / Colonna 4 → 4 (Naked Single)
46. Riga 7 / Colonna 2 → 2 (Naked Single)
47. Riga 5 / Colonna 2 → 4 (Full House)
48. Riga 7 / Colonna 1 → 8 (Full House)
49. Riga 9 / Colonna 4 → 3 (Naked Single)
50. Riga 9 / Colonna 5 → 8 (Full House)
51. Riga 5 / Colonna 3 → 9 (Naked Single)
52. Riga 5 / Colonna 4 → 2 (Full House)
53. Riga 8 / Colonna 1 → 9 (Naked Single)
54. Riga 8 / Colonna 3 → 4 (Full House)
55. Riga 1 / Colonna 5 → 5 (Naked Single)
56. Riga 3 / Colonna 5 → 3 (Full House)
57. Riga 9 / Colonna 8 → 9 (Naked Single)
58. Riga 9 / Colonna 7 → 4 (Full House)
59. Riga 6 / Colonna 1 → 5 (Naked Single)
60. Riga 1 / Colonna 4 → 8 (Naked Single)
61. Riga 4 / Colonna 4 → 7 (Naked Single)
62. Riga 6 / Colonna 4 → 9 (Full House)
63. Riga 8 / Colonna 7 → 7 (Naked Single)
64. Riga 1 / Colonna 7 → 9 (Full House)
65. Riga 8 / Colonna 8 → 8 (Full House)
66. Riga 3 / Colonna 6 → 4 (Naked Single)
67. Riga 2 / Colonna 8 → 2 (Naked Single)
68. Riga 2 / Colonna 6 → 9 (Full House)
69. Riga 1 / Colonna 6 → 2 (Full House)
70. Riga 4 / Colonna 1 → 2 (Naked Single)
71. Riga 6 / Colonna 6 → 3 (Naked Single)
72. Riga 4 / Colonna 6 → 5 (Full House)
73. Riga 4 / Colonna 3 → 3 (Full House)
74. Riga 6 / Colonna 3 → 7 (Full House)
75. Riga 3 / Colonna 1 → 7 (Naked Single)
76. Riga 1 / Colonna 1 → 4 (Full House)
77. Riga 1 / Colonna 8 → 7 (Full House)
78. Riga 3 / Colonna 8 → 5 (Full House)