Solution for Evil Sudoku #1257248619341

1
6
8
8
7
3
9
9
4
2
9
4
6
3
7
9
5
2
9
5
7
8
4
5
5
1
7

This Sudoku Puzzle has 73 steps and it is solved using Naked Single, Full House, Hidden Single, Locked Candidates Type 1 (Pointing), Locked Candidates Type 2 (Claiming), Naked Triple, Hidden Pair, undefined, AIC, Locked Pair, Continuous Nice Loop, Skyscraper, Sue de Coq techniques.

Naked Single Explanation
Hidden Single Explanation
Hidden Pair Explanation
Locked Candidates Explanation
Locked Candidates Explanation
Full House Explanation
Try To Solve This Puzzle

Solution Steps:

  1. Row 7 / Column 5 → 2 (Naked Single)
  2. Row 2 / Column 5 → 4 (Naked Single)
  3. Row 3 / Column 5 → 1 (Naked Single)
  4. Row 8 / Column 5 → 9 (Full House)
  5. Row 6 / Column 4 → 9 (Hidden Single)
  6. Row 1 / Column 1 → 9 (Hidden Single)
  7. Row 9 / Column 7 → 9 (Hidden Single)
  8. Row 2 / Column 1 → 5 (Hidden Single)
  9. Locked Candidates Type 1 (Pointing): 7 in b1 => r49c2<>7
  10. Locked Candidates Type 1 (Pointing): 5 in b2 => r4c4<>5
  11. Locked Candidates Type 1 (Pointing): 2 in b9 => r13c8<>2
  12. Locked Candidates Type 2 (Claiming): 3 in c1 => r79c2,r89c3<>3
  13. Naked Triple: 1,3,8 in r4c247 => r4c38<>3, r4c68<>1, r4c8<>8
  14. Hidden Pair: 4,7 in r4c8,r5c9 => r5c9<>6, r5c9<>8
  15. 2-String Kite: 3 in r1c3,r4c7 (connected by r4c2,r6c3) => r1c7<>3
  16. Locked Candidates Type 2 (Claiming): 3 in c7 => r6c8<>3
  17. XY-Wing: 1/6/3 in r7c6,r8c14 => r7c1<>3
  18. Row 7 / Column 1 → 8 (Naked Single)
  19. XY-Chain: 3 3- r3c8 -7- r4c8 -4- r5c9 -7- r5c1 -1- r8c1 -3 => r8c8<>3
  20. AIC: 3 3- r1c3 =3= r6c3 =5= r4c3 =7= r4c8 -7- r3c8 -3 => r1c89,r3c2<>3
  21. Locked Pair: 2,7 in r23c2 => r1c23,r9c2<>2
  22. Continuous Nice Loop: 1/3/6/8 7= r9c1 =3= r8c1 =1= r8c4 -1- r4c4 -8- r4c2 =8= r6c2 -8- r6c8 =8= r9c8 =2= r9c3 =7= r9c1 =3 => r5c4,r9c1<>1, r9c8<>3, r9c38<>6, r46c7<>8
  23. Skyscraper: 1 in r4c4,r5c1 (connected by r8c14) => r4c2,r5c6<>1
  24. X-Wing: 1 c26 r69 => r6c78<>1
  25. Row 1 / Column 8 → 1 (Hidden Single)
  26. Sue de Coq: r6c23 - {13568} (r6c78 - {368}, r4c3,r5c1 - {157}) => r5c3<>7
  27. Row 5 / Column 3 → 6 (Naked Single)
  28. XY-Chain: 2 2- r1c7 -6- r6c7 -3- r4c7 -1- r4c4 -8- r5c4 -2 => r1c4<>2
  29. Row 1 / Column 7 → 2 (Hidden Single)
  30. Finned X-Wing: 6 r18 c49 fr8c8 => r9c9<>6
  31. Hidden Pair: 1,6 in r9c26 => r9c6<>3
  32. Row 7 / Column 6 → 3 (Hidden Single)
  33. Row 3 / Column 8 → 3 (Hidden Single)
  34. Row 4 / Column 8 → 7 (Hidden Single)
  35. Row 4 / Column 3 → 5 (Naked Single)
  36. Row 5 / Column 9 → 4 (Naked Single)
  37. Row 4 / Column 6 → 4 (Naked Single)
  38. Row 6 / Column 3 → 3 (Naked Single)
  39. Row 5 / Column 6 → 2 (Naked Single)
  40. Row 1 / Column 3 → 4 (Naked Single)
  41. Row 4 / Column 2 → 8 (Naked Single)
  42. Row 6 / Column 7 → 6 (Naked Single)
  43. Row 2 / Column 6 → 6 (Naked Single)
  44. Row 5 / Column 4 → 8 (Naked Single)
  45. Row 1 / Column 2 → 3 (Naked Single)
  46. Row 8 / Column 3 → 2 (Naked Single)
  47. Row 9 / Column 3 → 7 (Full House)
  48. Row 4 / Column 4 → 1 (Naked Single)
  49. Row 4 / Column 7 → 3 (Full House)
  50. Row 6 / Column 6 → 5 (Full House)
  51. Row 9 / Column 6 → 1 (Full House)
  52. Row 8 / Column 4 → 6 (Full House)
  53. Row 6 / Column 2 → 1 (Naked Single)
  54. Row 6 / Column 8 → 8 (Full House)
  55. Row 5 / Column 7 → 1 (Full House)
  56. Row 2 / Column 7 → 8 (Full House)
  57. Row 5 / Column 1 → 7 (Full House)
  58. Row 1 / Column 4 → 5 (Naked Single)
  59. Row 1 / Column 9 → 6 (Full House)
  60. Row 3 / Column 4 → 2 (Full House)
  61. Row 9 / Column 1 → 3 (Naked Single)
  62. Row 8 / Column 1 → 1 (Full House)
  63. Row 9 / Column 2 → 6 (Naked Single)
  64. Row 7 / Column 2 → 4 (Full House)
  65. Row 7 / Column 8 → 6 (Full House)
  66. Row 8 / Column 8 → 4 (Naked Single)
  67. Row 8 / Column 9 → 3 (Full House)
  68. Row 9 / Column 8 → 2 (Full House)
  69. Row 9 / Column 9 → 8 (Full House)
  70. Row 2 / Column 9 → 7 (Naked Single)
  71. Row 2 / Column 2 → 2 (Full House)
  72. Row 3 / Column 2 → 7 (Full House)
  73. Row 3 / Column 9 → 5 (Full House)
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