Passaggi della soluzione:

1. Riga 4 / Colonna 6 → 2 (Hidden Single)
2. Riga 6 / Colonna 3 → 2 (Hidden Single)
3. Riga 8 / Colonna 4 → 2 (Hidden Single)
4. Riga 7 / Colonna 8 → 2 (Hidden Single)
5. Riga 2 / Colonna 2 → 2 (Hidden Single)
6. Riga 8 / Colonna 7 → 8 (Hidden Single)
7. Riga 6 / Colonna 8 → 8 (Hidden Single)
8. Riga 2 / Colonna 1 → 8 (Hidden Single)
9. Riga 4 / Colonna 2 → 8 (Hidden Single)
10. Locked Candidates Type 1 (Pointing): 5 in b5 => r5c23<>5
11. Riga 4 / Colonna 3 → 5 (Hidden Single)
12. Riga 4 / Colonna 1 → 9 (Hidden Single)
13. Riga 4 / Colonna 7 → 7 (Hidden Single)
14. Locked Candidates Type 1 (Pointing): 9 in b9 => r3c9<>9
15. X-Wing: 1 r48 c59 => r2c59<>1
16. Locked Candidates Type 1 (Pointing): 1 in b2 => r1c8<>1
17. Hidden Rectangle: 4/5 in r2c79,r6c79 => r2c9<>4
18. Sashimi X-Wing: 6 c38 r59 fr7c3 fr8c3 => r9c2<>6
19. Finned Swordfish: 6 c348 r579 fr8c3 => r7c2<>6
20. Discontinuous Nice Loop: 4 r2c7 -4- r2c5 =4= r8c5 =1= r8c9 -1- r9c7 =1= r2c7 => r2c7<>4
21. Discontinuous Nice Loop: 4 r7c2 -4- r7c7 -3- r9c7 =3= r9c2 =5= r7c2 => r7c2<>4
22. Grouped Discontinuous Nice Loop: 4 r5c1 -4- r8c1 -6- r78c3 =6= r5c3 =7= r5c1 => r5c1<>4
23. Grouped Discontinuous Nice Loop: 4 r7c9 -4- r3c9 -3- r2c9 -5- r2c7 =5= r6c7 =4= r79c7 -4- r7c9 => r7c9<>4
24. Sashimi Swordfish: 4 c159 r368 fr2c5 => r3c6<>4
25. Grouped Discontinuous Nice Loop: 4 r8c9 -4- r3c9 -3- r2c9 -5- r2c7 =5= r6c7 =4= r79c7 -4- r8c9 => r8c9<>4
26. Almost Locked Set XY-Wing: A=r2c35 {347}, B=r3c469 {3478}, C=r123c8,r2c79 {134579}, X,Y=3,4, Z=7 => r3c1<>7
27. Riga 5 / Colonna 1 → 7 (Hidden Single)
28. Skyscraper: 3 in r2c5,r3c1 (connected by r6c15) => r2c3,r3c4<>3
29. Riga 3 / Colonna 4 → 8 (Naked Single)
30. Riga 3 / Colonna 6 → 7 (Naked Single)
31. Riga 7 / Colonna 6 → 8 (Hidden Single)
32. Hidden Rectangle: 4/7 in r1c38,r2c38 => r1c8<>4
33. XY-Chain: 1 1- r1c6 -4- r2c5 -3- r6c5 -6- r4c5 -1 => r5c6<>1
34. Riga 5 / Colonna 6 → 5 (Naked Single)
35. XYZ-Wing: 1/3/4 in r79c7,r9c6 => r9c8<>4
36. Locked Candidates Type 1 (Pointing): 4 in b9 => r6c7<>4
37. Riga 6 / Colonna 7 → 5 (Naked Single)
38. Riga 2 / Colonna 9 → 5 (Hidden Single)
39. 2-String Kite: 3 in r3c9,r9c2 (connected by r7c9,r9c7) => r3c2<>3
40. Sashimi Swordfish: 3 r269 c257 fr6c1 => r5c2<>3
41. W-Wing: 4/6 in r5c2,r8c1 connected by 6 in r3c12 => r6c1,r9c2<>4
42. Riga 6 / Colonna 9 → 4 (Hidden Single)
43. Riga 3 / Colonna 9 → 3 (Naked Single)
44. Riga 2 / Colonna 7 → 1 (Naked Single)
45. Riga 2 / Colonna 5 → 3 (Hidden Single)
46. Riga 1 / Colonna 4 → 1 (Naked Single)
47. Riga 1 / Colonna 6 → 4 (Full House)
48. Riga 9 / Colonna 6 → 1 (Full House)
49. Riga 6 / Colonna 5 → 6 (Naked Single)
50. Riga 6 / Colonna 1 → 3 (Full House)
51. Riga 9 / Colonna 8 → 6 (Naked Single)
52. Riga 4 / Colonna 5 → 1 (Naked Single)
53. Riga 5 / Colonna 4 → 3 (Full House)
54. Riga 8 / Colonna 5 → 4 (Full House)
55. Riga 4 / Colonna 9 → 6 (Full House)
56. Riga 5 / Colonna 8 → 1 (Full House)
57. Riga 7 / Colonna 9 → 9 (Naked Single)
58. Riga 8 / Colonna 9 → 1 (Full House)
59. Riga 9 / Colonna 4 → 5 (Naked Single)
60. Riga 7 / Colonna 4 → 6 (Full House)
61. Riga 8 / Colonna 1 → 6 (Naked Single)
62. Riga 3 / Colonna 1 → 4 (Full House)
63. Riga 8 / Colonna 3 → 9 (Full House)
64. Riga 9 / Colonna 2 → 3 (Naked Single)
65. Riga 9 / Colonna 7 → 4 (Full House)
66. Riga 7 / Colonna 7 → 3 (Full House)
67. Riga 2 / Colonna 3 → 7 (Naked Single)
68. Riga 2 / Colonna 8 → 4 (Full House)
69. Riga 3 / Colonna 8 → 9 (Naked Single)
70. Riga 1 / Colonna 8 → 7 (Full House)
71. Riga 3 / Colonna 2 → 6 (Full House)
72. Riga 1 / Colonna 2 → 9 (Naked Single)
73. Riga 1 / Colonna 3 → 3 (Full House)
74. Riga 7 / Colonna 2 → 5 (Naked Single)
75. Riga 7 / Colonna 3 → 4 (Full House)
76. Riga 5 / Colonna 2 → 4 (Full House)
77. Riga 5 / Colonna 3 → 6 (Full House)