- Code: Select all
`.---------.---------.---------.`

| . . . | . 2 . | . 4 . |

| 2 . . | . . . | 9 . . |

| 5 . . | 4 . . | . 8 . |

+---------+---------+---------+

| . 6 1 | . 9 2 | . . . |

| 7 . . | . . . | . . 4 |

| . . . | 3 4 . | 1 9 . |

+---------+---------+---------+

| . 8 . | . . 7 | . . 6 |

| . . 6 | . . . | . . 5 |

| . 4 . | . 3 . | . . . |

'---------'---------'---------'

my resolution without using pm

1. r2c3=4

(by cross-hatching, only possible place for a 4 in b1)

2. r4c1=4

(by cross-hatching, only possible place for a 4 in b4)

3. r8c6=4

(by cross-hatching, only possible place for a 4 in b8)

4. r7c7=4

(by cross-hatching, only possible place for a 4 in b9)

5. r1c1=6

(by cross-hatching, only possible place for a 6 in b1)

6. r1c3=8

(by cross-hatching, only possible place for a 8 in b1)

7. r6c1=8

(by cross-hatching, only possible place for a 8 in b4)

8. r6c6=6

(by cross-hatching, the only possible places for 6 in b6 is r5c78; so by cross-hatching the only place of 6 in b5 is r6c6)

9. r4c4=7

(only place a 7 can go in b5)

10. r6c9=7

(by cross-hatching, only place a 7 can go in b6)

11. r9c9=9

(by cross-hatching, only place a 9 can go in b9)

12. r9c4=6

(by cross-hatching, only place a 6 can go in b8)

13. r4c9=8

(by cross-hatching, the only possible places for 8 in b9 is r89c7; so by cross-hatching the only place a 8 can go in b6 is r4c9)

14. r3c9=2

(by cross-hatching, only place a 2 can go in c9)

15. r9c1=1

(by cross-hatching the only places 9 and 3 can go in c1 is r78c1)

16. r6c2=5

(by cross-hatching in b7, and using the fact that 1,9 are locked in r78c1, r79c3 are the only places a 5 can go;

so in r7 the only place for a 5 is r6c2)

17. r6c3=2

(full house: the only possible candidate for this cell in r6)

18. r8c2=2

(in b7 3,9 is locked in r78c1, by cross-hatching the only place for a 2 in b7 is r8c2)

19. r9c3=7

(in b7 3,9 is locked in r78c1, by cross-hatching the only place for a 7 in b7 is r9c3)

20. r7c3=5

(in b7 3,9 is locked in r78c1, so the only place a 5 can go in b7 is r7c3)

21. r7c4=2

(by cross-hatching, the only place a 2 can go in b8)

22. r9c6=5

(by cross-hatching, the only place a 5 can go in b9)

23. r9c7=8

(by cross-hatching, the only place an 8 can go in r9)

24. r9c8=2

(full house: the only possible candidate for this cell in r9)

25. r5c7=2

(by cross-hatching, the only place a 2 can go in b6)

26. r5c8=6

(by cross-hatching, the only place a 6 can go in b6)

27. r3c7=6

(by cross-hatching, the only place a 6 can go in b3)

28. r2c5=6

(by cross-hatching, the only place a 6 can go in b2)

29. r3c5=7

by cross-hatching, the only place a 7 can go in b2)

30. r5c5=5

(by cross-hatching, in b2 the only places for a 5 are r12c4; so by cross-hatching the only place left for a 5 in b5)

31. r8c5=8

(by cross-hatching, the only place left for an 8 in c5)

32. r8c4=9

(by cross-hatching, the only place left for a 9 in b8)

33. r7c5=1

(full house: the only possible candidate for this cell in b8)

34. r7c1=9

(by cross-hatching, the only place left for a 9 in b7)

35. r8c1=3

(full house: the only possible candidate for this cell in b7)

36. r7c8=3

(full house: the only possible candidate for this cell in r7)

37. r8c8=1

(by cross-hatching, the only place left for 1 in b9)

38. r8c7=7

(full house: the only possible candidate for this cell in b9)

39. r4c7=3

(by cross-hatching, the only place left for 3 in b6)

40. r4c8=5

(full house: the only possible candidate for this cell in b6)

41. r1c7=5

(full house: the only possible candidate for this cell in c7)

42. r2c8=7

(full house: the only possible candidate for this cell in c8)

43. r2c4=5

(by cross-hatching, the only place left for a 5 in b2)

44. r1c4=1

(naked single: only possible candidate for this cell)

45. r2c9=1

(by cross-hatching, the only place a 1 can go in c9 or b3)

46. r1c9=3

(full house: the only possible candidate for this cell in b3)

47. r3c2=1

(by cross-hatching, the only place a 1 can go in b1)

48. r2c6=8

(by cross-hatcing, the only place an 8 can go in b2)

49. r5c4=8

(by cross-hatching, the only place an 8 can go in b5)

50. r5c6=1

(full-house: the only possible candidate for this cell in b5)

51. r3c6=3

(by cross-hatching, the only place a 3 can go in b2)

52. r1c6=9

(full house: the only possible candidate for this cell in b2)

53. r3c3=9

(by cross-hatching, the only place a 9 can go in b1)

54. r2c2=3

(by cross-hatching, the only place a 3 can go in b1)

55. r1c2=7

(full house: the only possible candidate for this cell in b1)

56. r5c3=3

(by cross-hatching, the only place a 3 can go in b4)

57. r5c2=9

(full house: the only possible candidate for this cell in b4)