Passaggi della soluzione:

1. Locked Candidates Type 1 (Pointing): 3 in b1 => r79c2<>3
2. Hidden Pair: 1,7 in r4c3,r5c2 => r4c3<>4, r4c3<>9, r5c2<>6
3. Hidden Pair: 7,9 in r7c8,r9c9 => r7c8,r9c9<>3, r7c8<>8, r9c9<>2, r9c9<>4
4. Hidden Pair: 1,7 in r49c3 => r9c3<>4, r9c3<>5
5. AIC: 1 1- r3c5 =1= r9c5 =2= r9c7 =4= r3c7 -4- r3c4 =4= r4c4 =7= r4c3 =1= r9c3 -1- r7c2 =1= r7c6 -1 => r2c6,r9c5<>1
6. Riga 3 / Colonna 5 → 1 (Hidden Single)
7. XY-Chain: 3 3- r3c8 -2- r2c7 -6- r5c7 -8- r7c7 -3 => r3c7,r8c8<>3
8. Locked Candidates Type 2 (Claiming): 3 in c7 => r8c9<>3
9. Discontinuous Nice Loop: 9 r2c1 -9- r5c1 -6- r6c2 -2- r3c2 =2= r2c1 => r2c1<>9
10. Locked Candidates Type 1 (Pointing): 9 in b1 => r6c3<>9
11. Discontinuous Nice Loop: 3 r4c4 -3- r8c4 =3= r8c1 -3- r9c1 -4- r9c7 =4= r3c7 -4- r3c4 =4= r4c4 => r4c4<>3
12. Locked Candidates Type 1 (Pointing): 3 in b5 => r79c6<>3
13. Naked Triple: 1,7,9 in r9c369 => r9c2<>1, r9c2<>7, r9c5<>9
14. Riga 9 / Colonna 2 → 5 (Naked Single)
15. Riga 9 / Colonna 5 → 2 (Naked Single)
16. Riga 8 / Colonna 5 → 5 (Naked Single)
17. Riga 5 / Colonna 4 → 5 (Hidden Single)
18. Locked Candidates Type 2 (Claiming): 9 in c5 => r4c46,r6c6<>9
19. Locked Candidates Type 2 (Claiming): 2 in c7 => r2c89,r3c8<>2
20. Riga 3 / Colonna 8 → 3 (Naked Single)
21. Riga 1 / Colonna 2 → 3 (Hidden Single)
22. Naked Pair: 2,6 in r36c2 => r7c2<>6
23. Finned Swordfish: 7 r157 c258 fr1c9 => r2c8<>7
24. Swordfish: 7 r249 c349 => r1c9<>7
25. Naked Triple: 2,4,6 in r1c9,r23c7 => r2c9<>6
26. W-Wing: 1/7 in r2c9,r4c3 connected by 7 in r9c39 => r4c9<>1
27. XY-Chain: 9 9- r6c5 -8- r1c5 -7- r1c8 -5- r2c8 -1- r2c9 -7- r9c9 -9 => r6c9<>9
28. Discontinuous Nice Loop: 6/8/9 r2c3 =5= r2c8 =1= r2c9 =7= r2c4 -7- r4c4 -4- r3c4 =4= r3c7 -4- r9c7 -3- r7c7 -8- r5c7 =8= r5c5 =7= r1c5 -7- r1c8 -5- r1c3 =5= r2c3 => r2c3<>6, r2c3<>8, r2c3<>9
29. Riga 2 / Colonna 3 → 5 (Naked Single)
30. Riga 2 / Colonna 8 → 1 (Naked Single)
31. Riga 2 / Colonna 9 → 7 (Naked Single)
32. Riga 1 / Colonna 8 → 5 (Naked Single)
33. Riga 9 / Colonna 9 → 9 (Naked Single)
34. Riga 7 / Colonna 8 → 7 (Naked Single)
35. Riga 9 / Colonna 6 → 1 (Naked Single)
36. Riga 7 / Colonna 2 → 1 (Naked Single)
37. Riga 9 / Colonna 3 → 7 (Naked Single)
38. Riga 5 / Colonna 2 → 7 (Naked Single)
39. Riga 4 / Colonna 3 → 1 (Naked Single)
40. Riga 3 / Colonna 3 → 9 (Hidden Single)
41. Riga 5 / Colonna 9 → 1 (Hidden Single)
42. Riga 1 / Colonna 5 → 7 (Hidden Single)
43. Riga 4 / Colonna 4 → 7 (Hidden Single)
44. Riga 3 / Colonna 4 → 4 (Hidden Single)
45. Riga 1 / Colonna 9 → 4 (Hidden Single)
46. Riga 8 / Colonna 9 → 2 (Naked Single)
47. Riga 4 / Colonna 9 → 3 (Naked Single)
48. Riga 6 / Colonna 9 → 6 (Full House)
49. Riga 8 / Colonna 8 → 8 (Naked Single)
50. Riga 4 / Colonna 6 → 4 (Naked Single)
51. Riga 5 / Colonna 7 → 8 (Naked Single)
52. Riga 6 / Colonna 2 → 2 (Naked Single)
53. Riga 3 / Colonna 2 → 6 (Full House)
54. Riga 3 / Colonna 7 → 2 (Full House)
55. Riga 2 / Colonna 7 → 6 (Full House)
56. Riga 6 / Colonna 3 → 4 (Naked Single)
57. Riga 7 / Colonna 7 → 3 (Naked Single)
58. Riga 9 / Colonna 7 → 4 (Full House)
59. Riga 9 / Colonna 1 → 3 (Full House)
60. Riga 5 / Colonna 5 → 9 (Naked Single)
61. Riga 5 / Colonna 1 → 6 (Full House)
62. Riga 4 / Colonna 1 → 9 (Full House)
63. Riga 6 / Colonna 5 → 8 (Full House)
64. Riga 4 / Colonna 8 → 2 (Full House)
65. Riga 6 / Colonna 8 → 9 (Full House)
66. Riga 6 / Colonna 6 → 3 (Full House)
67. Riga 1 / Colonna 3 → 8 (Naked Single)
68. Riga 8 / Colonna 3 → 6 (Full House)
69. Riga 1 / Colonna 6 → 6 (Full House)
70. Riga 2 / Colonna 1 → 2 (Full House)
71. Riga 2 / Colonna 4 → 9 (Naked Single)
72. Riga 2 / Colonna 6 → 8 (Full House)
73. Riga 7 / Colonna 6 → 9 (Full House)
74. Riga 7 / Colonna 1 → 8 (Naked Single)
75. Riga 8 / Colonna 1 → 4 (Full House)
76. Riga 8 / Colonna 4 → 3 (Full House)
77. Riga 7 / Colonna 4 → 6 (Full House)