Passaggi della soluzione:

1. Riga 9 / Colonna 4 → 1 (Naked Single)
2. Riga 4 / Colonna 1 → 9 (Hidden Single)
3. Riga 6 / Colonna 9 → 5 (Hidden Single)
4. Riga 4 / Colonna 3 → 8 (Hidden Single)
5. Riga 4 / Colonna 9 → 7 (Hidden Single)
6. Riga 2 / Colonna 1 → 8 (Hidden Single)
7. Locked Candidates Type 1 (Pointing): 2 in b4 => r5c6<>2
8. Locked Candidates Type 1 (Pointing): 7 in b8 => r7c12<>7
9. Locked Candidates Type 1 (Pointing): 3 in b9 => r5c8<>3
10. XY-Wing: 4/6/3 in r4c7,r5c48 => r4c5<>3
11. Riga 4 / Colonna 7 → 3 (Hidden Single)
12. Locked Candidates Type 2 (Claiming): 4 in r4 => r5c6,r6c5<>4
13. Finned Swordfish: 6 r268 c579 fr2c6 => r3c5<>6
14. AIC: 2/4 2- r3c9 =2= r1c7 =1= r1c6 -1- r5c6 -6- r5c8 -4- r7c8 =4= r7c9 -4 => r7c9<>2, r3c9<>4
15. Discontinuous Nice Loop: 6 r8c7 -6- r6c7 =6= r6c5 =1= r2c5 -1- r1c6 =1= r1c7 =2= r8c7 => r8c7<>6
16. Naked Triple: 1,2,7 in r8c137 => r8c59<>2, r8c9<>1
17. Naked Triple: 2,6,9 in r389c9 => r27c9<>6, r2c9<>9
18. XYZ-Wing: 1/2/4 in r18c7,r2c9 => r2c7<>1
19. Naked Pair: 4,6 in r26c7 => r1c7<>4
20. Finned Swordfish: 1 r158 c167 fr5c2 => r6c1<>1
21. XY-Chain: 1 1- r2c9 -4- r2c7 -6- r6c7 -4- r5c8 -6- r5c6 -1 => r2c6<>1
22. Continuous Nice Loop: 3/4 6= r6c5 =1= r2c5 -1- r2c9 -4- r2c7 -6- r6c7 =6= r6c5 =1 => r6c5<>3, r13c8,r2c236<>4
23. Riga 5 / Colonna 4 → 3 (Hidden Single)
24. Locked Candidates Type 1 (Pointing): 4 in b3 => r2c5<>4
25. Skyscraper: 6 in r7c4,r8c9 (connected by r3c49) => r7c8,r8c5<>6
26. Riga 8 / Colonna 5 → 9 (Naked Single)
27. Riga 8 / Colonna 9 → 6 (Naked Single)
28. 2-String Kite: 6 in r2c7,r5c6 (connected by r5c8,r6c7) => r2c6<>6
29. Riga 2 / Colonna 6 → 9 (Naked Single)
30. Locked Pair: 3,5 in r2c23 => r2c5,r3c12<>3
31. Riga 3 / Colonna 5 → 3 (Hidden Single)
32. Riga 4 / Colonna 5 → 4 (Hidden Single)
33. Riga 4 / Colonna 6 → 2 (Full House)
34. Riga 9 / Colonna 6 → 5 (Naked Single)
35. Riga 7 / Colonna 5 → 2 (Hidden Single)
36. 2-String Kite: 2 in r1c7,r9c2 (connected by r8c7,r9c9) => r1c2<>2
37. Sue de Coq: r79c2 - {1235} (r2c2 - {35}, r8c13 - {127}) => r7c1<>1, r5c2<>5, r6c2<>3
38. Swordfish: 1 r267 c259 => r5c2<>1
39. Sue de Coq: r56c2 - {1247} (r279c2 - {1235}, r6c13 - {347}) => r5c3<>4, r3c2<>2
40. Skyscraper: 2 in r3c1,r9c2 (connected by r39c9) => r8c1<>2
41. X-Wing: 2 r18 c37 => r5c3<>2
42. Riga 5 / Colonna 3 → 5 (Naked Single)
43. Riga 2 / Colonna 3 → 3 (Naked Single)
44. Riga 2 / Colonna 2 → 5 (Naked Single)
45. Riga 7 / Colonna 1 → 5 (Hidden Single)
46. Riga 6 / Colonna 1 → 3 (Hidden Single)
47. XY-Wing: 4/7/2 in r5c2,r68c3 => r9c2<>2
48. Riga 9 / Colonna 2 → 3 (Naked Single)
49. Riga 7 / Colonna 2 → 1 (Naked Single)
50. Riga 9 / Colonna 8 → 9 (Naked Single)
51. Riga 9 / Colonna 9 → 2 (Full House)
52. Riga 7 / Colonna 9 → 4 (Naked Single)
53. Riga 8 / Colonna 1 → 7 (Naked Single)
54. Riga 8 / Colonna 3 → 2 (Full House)
55. Riga 8 / Colonna 7 → 1 (Full House)
56. Riga 7 / Colonna 8 → 3 (Full House)
57. Riga 1 / Colonna 8 → 8 (Naked Single)
58. Riga 3 / Colonna 9 → 9 (Naked Single)
59. Riga 2 / Colonna 9 → 1 (Full House)
60. Riga 3 / Colonna 1 → 2 (Naked Single)
61. Riga 5 / Colonna 1 → 1 (Full House)
62. Riga 1 / Colonna 7 → 2 (Naked Single)
63. Riga 1 / Colonna 4 → 7 (Naked Single)
64. Riga 3 / Colonna 8 → 6 (Naked Single)
65. Riga 2 / Colonna 7 → 4 (Full House)
66. Riga 2 / Colonna 5 → 6 (Full House)
67. Riga 5 / Colonna 8 → 4 (Full House)
68. Riga 6 / Colonna 7 → 6 (Full House)
69. Riga 6 / Colonna 5 → 1 (Full House)
70. Riga 5 / Colonna 6 → 6 (Full House)
71. Riga 5 / Colonna 2 → 2 (Full House)
72. Riga 1 / Colonna 3 → 4 (Naked Single)
73. Riga 6 / Colonna 3 → 7 (Full House)
74. Riga 6 / Colonna 2 → 4 (Full House)
75. Riga 7 / Colonna 4 → 6 (Naked Single)
76. Riga 3 / Colonna 4 → 8 (Full House)
77. Riga 7 / Colonna 6 → 7 (Full House)
78. Riga 3 / Colonna 6 → 4 (Naked Single)
79. Riga 1 / Colonna 6 → 1 (Full House)
80. Riga 1 / Colonna 2 → 9 (Full House)
81. Riga 3 / Colonna 2 → 7 (Full House)