Passaggi della soluzione:

1. Riga 4 / Colonna 7 → 5 (Hidden Single)
2. Riga 6 / Colonna 3 → 4 (Hidden Single)
3. Riga 1 / Colonna 2 → 4 (Hidden Single)
4. Riga 9 / Colonna 8 → 4 (Hidden Single)
5. Riga 6 / Colonna 7 → 3 (Hidden Single)
6. Riga 4 / Colonna 3 → 7 (Hidden Single)
7. Riga 9 / Colonna 9 → 6 (Hidden Single)
8. Riga 4 / Colonna 1 → 3 (Hidden Single)
9. Riga 4 / Colonna 5 → 9 (Naked Single)
10. Riga 8 / Colonna 9 → 7 (Hidden Single)
11. Locked Triple: 1,3,9 in r1c456 => r1c3,r2c45,r3c46<>1, r1c38,r23c4,r3c6<>9, r1c8,r3c46<>3
12. Riga 3 / Colonna 8 → 3 (Hidden Single)
13. Locked Candidates Type 1 (Pointing): 5 in b7 => r3c2<>5
14. Locked Candidates Type 1 (Pointing): 1 in b9 => r2c7<>1
15. Naked Triple: 1,2,9 in r358c2 => r79c2<>1, r79c2<>2, r79c2<>9
16. Hidden Pair: 3,4 in r8c45 => r8c45<>1, r8c4<>2, r8c4<>9
17. W-Wing: 7/5 in r3c6,r9c2 connected by 5 in r7c26 => r9c6<>7
18. Discontinuous Nice Loop: 1/6 r6c5 =7= r6c6 -7- r3c6 -5- r2c5 =5= r9c5 =7= r6c5 => r6c5<>1, r6c5<>6
19. Riga 6 / Colonna 5 → 7 (Naked Single)
20. Riga 6 / Colonna 8 → 6 (Hidden Single)
21. Empty Rectangle: 9 in b3 (r6c19) => r2c1<>9
22. Finned X-Wing: 1 r69 c16 fr9c4 fr9c5 => r7c6<>1
23. Grouped Discontinuous Nice Loop: 9 r7c4 -9- r7c8 =9= r5c8 -9- r6c9 =9= r6c1 -9- r9c1 =9= r9c46 -9- r7c4 => r7c4<>9
24. Grouped Discontinuous Nice Loop: 9 r7c6 -9- r7c8 =9= r5c8 -9- r6c9 =9= r6c1 -9- r9c1 =9= r9c46 -9- r7c6 => r7c6<>9
25. Locked Candidates Type 1 (Pointing): 9 in b8 => r9c1<>9
26. Locked Candidates Type 1 (Pointing): 9 in b7 => r8c7<>9
27. Discontinuous Nice Loop: 9 r2c3 -9- r2c7 =9= r7c7 =1= r7c4 -1- r9c5 -5- r2c5 =5= r2c3 => r2c3<>9
28. Locked Candidates Type 1 (Pointing): 9 in b1 => r3c9<>9
29. Discontinuous Nice Loop: 2 r8c1 -2- r9c1 -1- r9c5 -5- r2c5 =5= r3c6 =7= r3c4 =6= r3c1 =8= r8c1 => r8c1<>2
30. Almost Locked Set XZ-Rule: A=r5c2356 {12369}, B=r269c1 {1269}, X=9, Z=6 => r2c5<>6
31. Riga 5 / Colonna 5 → 6 (Hidden Single)
32. Almost Locked Set XZ-Rule: A=r269c1 {1269}, B=r346c9 {1289}, X=9, Z=1 => r3c1<>1
33. Almost Locked Set XY-Wing: A=r2c79 {129}, B=r69c1 {129}, C=r346c9 {1289}, X,Y=1,9, Z=2 => r2c1<>2
34. Locked Candidates Type 1 (Pointing): 2 in b1 => r58c3<>2
35. XY-Chain: 1 1- r2c1 -6- r2c4 -4- r2c5 -5- r9c5 -1 => r9c1<>1
36. Riga 9 / Colonna 1 → 2 (Naked Single)
37. Riga 5 / Colonna 2 → 2 (Hidden Single)
38. Riga 8 / Colonna 7 → 2 (Hidden Single)
39. Riga 2 / Colonna 7 → 9 (Naked Single)
40. Riga 7 / Colonna 7 → 1 (Full House)
41. Riga 7 / Colonna 8 → 9 (Full House)
42. Riga 5 / Colonna 8 → 8 (Naked Single)
43. Riga 1 / Colonna 8 → 2 (Full House)
44. Riga 4 / Colonna 9 → 2 (Naked Single)
45. Riga 4 / Colonna 4 → 8 (Full House)
46. Riga 6 / Colonna 9 → 9 (Full House)
47. Riga 1 / Colonna 3 → 8 (Naked Single)
48. Riga 2 / Colonna 9 → 1 (Naked Single)
49. Riga 3 / Colonna 9 → 8 (Full House)
50. Riga 6 / Colonna 1 → 1 (Naked Single)
51. Riga 5 / Colonna 3 → 9 (Full House)
52. Riga 6 / Colonna 6 → 2 (Full House)
53. Riga 2 / Colonna 1 → 6 (Naked Single)
54. Riga 8 / Colonna 3 → 1 (Naked Single)
55. Riga 2 / Colonna 4 → 4 (Naked Single)
56. Riga 3 / Colonna 1 → 9 (Naked Single)
57. Riga 8 / Colonna 1 → 8 (Full House)
58. Riga 3 / Colonna 3 → 5 (Naked Single)
59. Riga 2 / Colonna 3 → 2 (Full House)
60. Riga 2 / Colonna 5 → 5 (Full House)
61. Riga 3 / Colonna 2 → 1 (Full House)
62. Riga 8 / Colonna 2 → 9 (Naked Single)
63. Riga 8 / Colonna 4 → 3 (Naked Single)
64. Riga 8 / Colonna 5 → 4 (Full House)
65. Riga 3 / Colonna 6 → 7 (Naked Single)
66. Riga 3 / Colonna 4 → 6 (Full House)
67. Riga 9 / Colonna 5 → 1 (Naked Single)
68. Riga 1 / Colonna 5 → 3 (Full House)
69. Riga 5 / Colonna 4 → 1 (Naked Single)
70. Riga 5 / Colonna 6 → 3 (Full House)
71. Riga 7 / Colonna 6 → 5 (Naked Single)
72. Riga 1 / Colonna 4 → 9 (Naked Single)
73. Riga 1 / Colonna 6 → 1 (Full House)
74. Riga 9 / Colonna 6 → 9 (Full House)
75. Riga 7 / Colonna 2 → 7 (Naked Single)
76. Riga 7 / Colonna 4 → 2 (Full House)
77. Riga 9 / Colonna 4 → 7 (Full House)
78. Riga 9 / Colonna 2 → 5 (Full House)