Pasos de la solución:

1. Fila 9 / Columna 6 → 6 (Naked Single)
2. Fila 9 / Columna 8 → 8 (Hidden Single)
3. Fila 6 / Columna 9 → 8 (Hidden Single)
4. Fila 7 / Columna 2 → 6 (Hidden Single)
5. Fila 5 / Columna 4 → 8 (Hidden Single)
6. Fila 2 / Columna 5 → 8 (Hidden Single)
7. Fila 3 / Columna 3 → 8 (Hidden Single)
8. Fila 7 / Columna 1 → 8 (Hidden Single)
9. Fila 7 / Columna 3 → 4 (Hidden Single)
10. Locked Candidates Type 1 (Pointing): 6 in b2 => r46c4<>6
11. Locked Candidates Type 1 (Pointing): 9 in b4 => r12c1<>9
12. Naked Triple: 2,3,7 in r46c3,r5c2 => r46c1<>3, r6c1<>7
13. Naked Triple: 2,3,9 in r7c56,r8c5 => r7c4<>2, r79c4<>3, r7c4<>9
14. Locked Candidates Type 1 (Pointing): 3 in b8 => r46c5<>3
15. Finned X-Wing: 3 r59 c27 fr5c8 => r46c7<>3
16. Finned X-Wing: 7 c19 r28 fr3c9 => r2c78<>7
17. Finned Swordfish: 3 r159 c278 fr1c1 => r3c2<>3
18. Locked Candidates Type 1 (Pointing): 3 in b1 => r1c8<>3
19. W-Wing: 7/3 in r5c2,r8c1 connected by 3 in r1c12 => r9c2<>7
20. Locked Candidates Type 1 (Pointing): 7 in b7 => r8c79<>7
21. Locked Candidates Type 2 (Claiming): 7 in c9 => r3c78<>7
22. Finned Swordfish: 9 c268 r137 fr2c8 => r3c7<>9
23. Discontinuous Nice Loop: 3 r3c7 -3- r9c7 =3= r9c2 -3- r1c2 =3= r1c1 =4= r1c6 -4- r3c6 =4= r3c7 => r3c7<>3
24. Discontinuous Nice Loop: 3 r5c8 -3- r5c2 -7- r3c2 =7= r3c9 =3= r3c8 -3- r5c8 => r5c8<>3
25. X-Wing: 3 r59 c27 => r1c2,r78c7<>3
26. Fila 1 / Columna 1 → 3 (Hidden Single)
27. Fila 8 / Columna 1 → 7 (Naked Single)
28. Fila 2 / Columna 1 → 4 (Naked Single)
29. Fila 1 / Columna 6 → 4 (Hidden Single)
30. Fila 3 / Columna 7 → 4 (Hidden Single)
31. XY-Chain: 2 2- r4c3 -3- r5c2 -7- r5c8 -1- r5c6 -2 => r4c45<>2
32. XY-Chain: 2 2- r5c6 -1- r5c8 -7- r5c2 -3- r9c2 -5- r8c3 -3- r8c5 -9- r7c6 -2 => r3c6<>2
33. Fila 3 / Columna 4 → 2 (Hidden Single)
34. Finned X-Wing: 1 r35 c68 fr5c7 => r6c8<>1
35. XY-Chain: 9 9- r3c2 -7- r2c3 -5- r8c3 -3- r8c5 -9- r7c6 -2- r5c6 -1- r3c6 -9 => r3c8<>9
36. XY-Chain: 1 1- r3c8 -3- r3c9 -7- r3c2 -9- r1c2 -5- r9c2 -3- r5c2 -7- r5c8 -1 => r2c8<>1
37. X-Wing: 1 c68 r35 => r5c7<>1
38. XY-Chain: 7 7- r5c2 -3- r9c2 -5- r1c2 -9- r3c2 -7- r3c9 -3- r3c8 -1- r5c8 -7 => r5c7<>7
39. XY-Chain: 3 3- r3c9 -7- r3c2 -9- r3c6 -1- r5c6 -2- r5c7 -3 => r4c9<>3
40. XY-Chain: 9 9- r7c6 -2- r5c6 -1- r5c8 -7- r5c2 -3- r9c2 -5- r8c3 -3- r8c5 -9 => r7c5<>9
41. XY-Chain: 3 3- r3c8 -1- r3c6 -9- r7c6 -2- r7c5 -3 => r7c8<>3
42. Fila 7 / Columna 5 → 3 (Hidden Single)
43. Fila 8 / Columna 5 → 9 (Naked Single)
44. Fila 4 / Columna 5 → 6 (Naked Single)
45. Fila 6 / Columna 5 → 2 (Full House)
46. Fila 7 / Columna 6 → 2 (Naked Single)
47. Fila 4 / Columna 9 → 5 (Naked Single)
48. Fila 5 / Columna 6 → 1 (Naked Single)
49. Fila 3 / Columna 6 → 9 (Full House)
50. Fila 5 / Columna 8 → 7 (Naked Single)
51. Fila 1 / Columna 4 → 6 (Naked Single)
52. Fila 2 / Columna 4 → 1 (Full House)
53. Fila 3 / Columna 2 → 7 (Naked Single)
54. Fila 5 / Columna 2 → 3 (Naked Single)
55. Fila 5 / Columna 7 → 2 (Full House)
56. Fila 2 / Columna 3 → 5 (Naked Single)
57. Fila 1 / Columna 2 → 9 (Full House)
58. Fila 9 / Columna 2 → 5 (Full House)
59. Fila 8 / Columna 3 → 3 (Full House)
60. Fila 1 / Columna 8 → 5 (Full House)
61. Fila 3 / Columna 9 → 3 (Naked Single)
62. Fila 3 / Columna 8 → 1 (Full House)
63. Fila 4 / Columna 3 → 2 (Naked Single)
64. Fila 6 / Columna 3 → 7 (Full House)
65. Fila 4 / Columna 7 → 1 (Naked Single)
66. Fila 9 / Columna 4 → 7 (Naked Single)
67. Fila 7 / Columna 4 → 5 (Full House)
68. Fila 9 / Columna 7 → 3 (Full House)
69. Fila 8 / Columna 9 → 6 (Naked Single)
70. Fila 2 / Columna 9 → 7 (Full House)
71. Fila 8 / Columna 7 → 5 (Full House)
72. Fila 7 / Columna 8 → 9 (Naked Single)
73. Fila 7 / Columna 7 → 7 (Full House)
74. Fila 4 / Columna 1 → 9 (Naked Single)
75. Fila 4 / Columna 4 → 3 (Full House)
76. Fila 6 / Columna 1 → 1 (Full House)
77. Fila 6 / Columna 4 → 9 (Full House)
78. Fila 6 / Columna 7 → 6 (Naked Single)
79. Fila 2 / Columna 7 → 9 (Full House)
80. Fila 2 / Columna 8 → 6 (Full House)
81. Fila 6 / Columna 8 → 3 (Full House)