Assassin 68

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gary w
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assassin 68 v1.5

Post by gary w »

Cathy,I don't follow your second preliminary step in your wt!!
For the 27/4 cage you say it must have an 8 and a 9.Why not 9765??
Para
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Post by Para »

Good morning all.

Here's last nights effort on Assassin 65V2. It is probably a high 1.75 because it uses no hypotheticals, mostly creative combination work.
Solved this one in my second attempt. First try i went to about step 25. Then couldn't see the next "obvious" step. The second attempt broke it open. Luckily spotted a logical flaw somewhere along and could correct it. The flaw did lead to the correct solution.
Now only got the V3 left. Hope i can work it in a similar way, because i can't think of any other way to tackle this pattern.

Enjoy! :D

Ok this is the final draft. I couldn't get that stupid ste to work, kept making mistakes. Just too difficutl so split it up in smaller steps. Now i am almost sure it is without mistakes. Other wise i give up.

Walk-Through Assassin 68V2

1. R12C5 = {18/27/36/45}: no 9

2. 19(5) at R1C7 = {12349/12358/12367/12457/13456}: 1 locked for N3

3. 14(4) at R2C1 = {1238/1247/1256/1346/2345}: no 9

4. 10(3) at R5C3 = {127/136/145/235}: no 8,9

5. R67C5 = {39/48/57}: no 1,2,6

6. R89C1 = {59/68}: no 1,2,3,4,7

7. 11(3) at R8C8 = {128/137/146/236/245}: no 9

8. R89C9 = {69/78}: no 1,2,3,4,5

9. 24(3) at R1C4 = {789} -->> locked within cage: R2C56: no 7,8,9
9a. Clean up: R1C5: no 7,8

10. 22(3) at R1C6 = {589/679}: no 1,2,3,4; 9 locked within cage -->> R2C4: no 9
10a. R2C6 needs one of {56} -->> R1C6 + R2C7: no 5,6

11. Naked Triple {789} in R2C347 -->> locked for R2

12. Naked Triple {789} in R1C46 + R2C4 -->> locked for N2
12a. 9 in N2 locked for R1
12b. Clean up: R2C5: no 1,2
12c. Killer Pair {56} in R12C5 + R2C6 -->> locked for N2
12d. 1 and 2 in N2 locked for R3 and 21(5) at R3C4

13. 21(5) at R3C4 needs {12} and one of {34} in R3C456 -->> 21(5) = {12369/12378/12459}:{12468} blocked by R12C5(removes all combinations for this cage) -->> R45C5 = {59/69/78}: no 3,4

14. R12C5 = {5|6..}; R45C5 = {5|6|7..} -->> R67C5 = {39/48}: {57} blocked by R12C5: R45C5: no 5,7
14a. Killer Pair {89} in R45C5 + R67C5 -->> locked for C5
14b. Killer Pair {34} in R12C5 + R67C5 -->> locked for C5

15. 45 on R89: 2 innies: R8C47 = 12 = {39/48/57}: no 1,2,6

16. 45 on N7: 2 outies: R6C1 + R7C4 = 12 = {39/48/57/66}: no 1,2

17. 45 on N9: 2 outies: R6C9 + R7C6 = 11 = {29/38/47/56}: no 1

18. 45 on C12: 2 outies: R19C3 = {16/25/34}: no 7,8,9

19. 45 on C89: 2 outies: R19C7 = 5 = {14/23}: no 5,6,7,8

20. 45 on C6789: 3 innies: R389C6 = 8 = {125/134}: no 6,7,8,9; 1 locked for C6
20a. 1 in N5 locked for C4

21. 45 on R9: 2 innies and 2 outies: R8C28 + 10 = R9C19: Max R9C19 = 17 -->> Max R8C28 = 7: no 7,8,9

22. 45 in N1: 2 innies and 2 outies: R4C12 + 10 = R23C3: Max R23C3 = 17 -->> Max R4C12 = 7: no 7,8; Min R4C12 = 3 -->> Min R23C3 = 13: no 3

23. 13(3) at R7C3 = {139/148/157/238/247/256/346}: Min R7C4 + R8C3 = 7 -->> R7C3: no 7,8,9
23a. When {157/256}, {12} in R7C3 -->> R7C3: no 5

24. 45 on C123: 2 outies and 3 innies: R67C4 + 15 = R234C3: Max R234C3 = 24 -->> Max R67C4 = 9: R6C4: no 7; R7C4: no 9; Min R67C4 = 4 -->> Min R234C3 = 19: no 1
24a. Clean up: R6C1: no 3

25. R12C5 = {4|6..}; R67C5 = {4|9..} -->> R45C5 = {59/78}: {69} blocked by R12C5 + R67C5: no 6

26. 45 on N8: 3 innies: R7C456 = 19 -->> R7C46 = 10/11/15/16

27. 45 on R89: 4 outies R7C3478 = 16: R7C46 = 10/11: (15/16) blocked-->> R7C37 = 5/6: no 6,7,8,9
27a. R7C46 = 10/11 -->> R7C6: no 9; R7C5: no 3,4(step 26)
27b. Clean up: R6C5: no 8,9; R6C9: no 2

28. R7C456 = 19: [892]/{3[9]7}/{4[9]6}/{4[8]7}/{5[8]6}: R7C6: no 8
28a. Clean up: R6C9: no 3

29. 18(3) at R6C1 = {279/378/459/468}: {189/369/567} blocked by R89C1: no 1

30. 45 on N9: 1 outie + 2 innies: R7C6 + 4 = R7C89: R7C89: no 4: Min R7C89 = 6

31. 45 on N7: 1 outie + 2 innies: R7C4 + 6 = R7C12: R7C12: no 6: Min R7C12 = 9

32. 45 on N89: 4 innies: R7C4589 = 22: Min R7C89 = 6 -->> Max R7C45 = 16: R7C4: no 8
32a. Clean up: R6C1: no 4; R7C6: no 2(step 28); R6C9: no 9

33. 18(3) at R6C1 = [5]{49}/[6]{48}/[7]{29}/[7]{38}/[8]{37}/[9]{27}/[9]{45}

34. 13(3) at R7C3 = [139/148]/[1]{57}/[238]/[265]: [2]{47} and {3[6]4} blocked by combination for 18(3) at R6C1: R7C3 = {12}; R8C3 = {5789}
34a. Clean up: R8C7: no 8,9

35. 15(3) at R7C6 = [627/645/654/357/537/735/753]: R7C6: no 4; R7C7: no 1
35a. Clean up: R6C9: no 7

36. 15(3) at R6C9 = [4]{29}/[5]{19/28/37}: [4]{38/56},[6]{27} and [8]{25} blocked by combinations for 15(3) at R7C3,{168} blocked by 15(2) at R8C9: R6C9 = {45}, R7C89 = {19/28/29/37}: no 5,6
36a. Clean up: R7C6: no 3,5

37. R7C456 = [397/496/487/586]: R7C6: no 6,7
37a. R7C6 = 6(hidden); R2C6 = 5; R6C9 = 5(step 17)
37b. Clean up: R7C4: no 3(step 37); R6C1: no 6,9
37c. R1C6 + R2C7 = {89}: R1C89 + R2C4: no 8
37d. R2C4 = 7

38. R12C5 = {36}(last combo); locked for C5 and N2
38a. R67C5 = [48]; R7C4 = 5(step 37); R6C1 = 7(step 16)

39. R7C12 = {29}(last combo) -->> locked for R7 and N7
39a. R89C1 = {68}(last combo) -->> locked for C1 and N7
39b. R8C3 = 7; R7C3 = 1; R8C7 = 5(step 15); R7C7 = 4
39c. R9C5 = 7(hidden)

40. 12(3) at R9C4 = 7{14/23}: no 9
40a. R8C4 = 9(hidden); R1C46 = [89]; R2C37 = [98]
40b. R9C9 = 9(hidden); R8C9 = 6; R89C1 = [86]; R9C8 = 8(hidden)

41. R7C89 = {37} -->> locked for N9

42. R19C7 = [32](step 19; last combo)
42a.R12C5 = [63]; R8C8 = 1; R8C56 = [23]; R8C2 = 4; R9C46 = [41]
42b. R6C456 = [214]; R3C9 = 7; R7C89 = [73]; R1C2 = 7(hidden)

43. 7 in C6 locked within 25(4) cage at R3C6
43a. R4C6 = 7(hidden); R5C7 = 7(hidden)

44. R6C67 = [26](last combo)
44a. R45C7 = [91]; R6c34 = [31]; R5C3 = 6

45. 14(4) at R2C1 = {2345}: no 1

And the rest is all singles.

I checked it against Mike's walk-through. Exactly the same opening digit. I think you are kinda forced to get to that one, because this pattern forces you to work in one part of the puzzle, just because the rest doesn't give away anything.

greetings

Para
Last edited by Para on Mon Nov 26, 2007 5:27 am, edited 3 times in total.
CathyW
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Re: assassin 68 v1.5

Post by CathyW »

gary w wrote:Cathy,I don't follow your second preliminary step in your wt!!
For the 27/4 cage you say it must have an 8 and a 9.Why not 9765??
Good question! An oversight on my part. I'll have to check through the rest of the WT later to see what effect that has. Bother! :oops:
sudokuEd
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Post by sudokuEd »

Para wrote:First try i went to about step 25.
Hmm - must be rusty: :wink: only got to step 25 on the second attempt.

Cheers
Ed
[edit: deleted steps. Para - do you want to post your valid ones and I'll add?]
Last edited by sudokuEd on Wed Sep 19, 2007 12:07 pm, edited 1 time in total.
CathyW
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Post by CathyW »

V1.5 WT Easier still on the 3rd attempt!!

Prelims

a) 17(2) r12c5 = {89} n/e N2/c5
b) 27(4) @ r2c1 = {3789/4689/5679} Must have 9 -> r56c1 <> 9 (see all cells of 27(4))
c) 22(3) N6 = {589/679} 9 n/e N6
d) 6(2) r67c5 = {15/24}
e) 19(3) @ r7c6 and r8c4: no 1
f) 13(2) r89c1 = {49/58/67}
g) 8(3) N7 = {125/134} 1 n/e N7
h) 11(3) r9c456: no 9
i) 10(2) r89c9: no 5


1. Outies c12: r19c3 = 9 = [45/54/63/72/81]

2. Outies c89: r19c7 = 17 = {89} n/e c7
a) NP {89} r1c57 n/e r1 -> r9c3 <> 1 -> 1 locked r89c2 n/e c2
b) r89c8 of 16(3) = (1…7)
c) r7c6 = (89) (because max from r78c7 = 6+7 = 13 thus r7c6 is min 6 but can’t be 6 or 7.) -> r78c7 <> 2
d) 19(3) r8c456: {289}blocked by r7c6 -> r8c456 <> 2

3. KP {89} N8: r7c6 and 19(3) r8c456 = {379/469/478/568} must have at least one of 8,9 -> 11(3) r9c456 <> 8, r7c4 <> 8,9

4. Innies r89: r8c37 = 13 = [67/76/85/94]

5. Outies r789: r6c159 = 15 = {168/258/267/348/357/456}

6. Outies N7: r6c1 + r7c4 = 10 = [82]/{37/46/55}

7. Outies N9: r6c9 + r7c6 = 14 = [59/68]
a) split 15(3) = [816/825/726]/{456}
b) KP r9c6 and 22(3) N6: r4c789, r56c7 <> 5,6
c) combo analysis 14(3) @ r9c6: r7c89 <> 4, 9

8. Innies N8: r7c456 = 15 = [258/348/618/249/429]

9. Innies r8: r8c1289 = 13 = 7{123}/{1246/1345}
Clean up: r9c1 <> 4,5; r9c9 <> 1,2,3

10. 16(3) @ r7c3: r7c4+r8c3 is min 2+6 = 9 -> r7c3 <> 9

11. 16(3) @ r1c4: r12c4 is max 6+7 = 13 -> r2c3 is min 3

12. 9 locked r9c79 in N9 -> r9c1 <> 9 -> r8c1 <> 4
a) split 13(4) = 7{123}/6{124}/5{134} (r8c289 = (1234)) -> r9c9 <> 4
b) ca 16(3) N9: r9c8 <> 1,2

13. 2 locked to split 13(4) in r8c1289
a) split 13(4) = 7{123}/6{124}
b) 13(2) r89c1 = {67} n/e N7/c1
c) split 15(3) r6c159 = [816/825/456/546]

14. 18(3) @ r6c1 = {459} only available combo.
a) 9 locked r7c12 -> r8c3 = 8, r7c6 = 8, r78c7 = [65], r6c9 = 6
b) r6c15 = {45} n/e r6 -> r7c5 = (12)
c) r7c89 = {17} n/e r7/N9 -> r7c5 = 2, r6c5 = 4, r6c1 = 5, r7c34 = [35]
d) r7c12 = {49} n/e N7 -> 8(3) N7 = {125}
e) 10(2) N9 = [28] only option -> r8c2 = 1, r9c7 = 9, r89c8 = {34} n/e c8, r1c7 = 8, r1c5 = 9, r2c5 = 8
f) clean up: r1c3 = (47)

15. 19(3) r8c456 = {379/469} -> r8c46 <> 6

16. 11(3) r9c456 = {137/146}

17. 27(4) @ r2c1 = {389}7 ({4689} blocked by r7c1 since 6 would have to go in r4c2)
a) {389} n/e c1 -> r7c1 = 4, r7c2 = 9 -> r15c1 = {12}
b) r56c2 of 13(3) N4 = [48]/{38} 8 n/e N4/c2
c) HS r3c1 = 8

18. Innies N1: r2c1+r23c3 = 17 = [359/395/971/962]
a) 20(5) N1 = {12467/13457/23456}

19. Innies N3: r79c23 = 15 = {1239/1257/1347} must have 1 -> 30(5) <> 1

20. Innies c1234: r389c4 = 15 = 2[76/94] only options.
a) 11(3) r9c456 = {146}
b) 19(3) r8c456 = [739] -> r9c456 = [614]
c) NS: r89c1 = [67], r89c8 = [43]

21. Innies c6789: r3c6 = 1

Straightforward from here
:)
Last edited by CathyW on Sun Sep 23, 2007 6:29 pm, edited 2 times in total.
mhparker
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Post by mhparker »

sudokuEd wrote:Hmm - must be rusty: :wink: only got to step 25 on the second attempt.
Who's this "Ed" guy? Reminds me of someone I used to know around here... :wink:

Here's my V2 attempt. Will be interesting to compare notes with Ed + Para:

[Edit: I would rate it around 1.75 (i.e., roughly A60RP level).]

Assassin 68 V2 Walkthrough

1. 9(2)n2 = {18/27/36/45} (no 9)

2. 19(5)n3 = {12349/12358/12367/12457/13456}
2a. -> 1 locked for n3

3. 14(3)n14 = {1238/1247/1256/1346/2345} (no 9)

4. 10(3)n45 = {127/136/145/235} (no 8,9)

5. 12(2)n58 = {39/48/57} (no 1,2,6)

6. 14(2)n7 = {59/68} (no 1,2,3,4,7)

7. 11(3)n9 = {128/137/146/236/245} (no 9)

8. 15(2)n9 = {69/78} (no 1,2,3,4,5)

9. 24(3)n12 = {789}
9a. CPE: no 7,8,9 in r2c56
9b. Cleanup: no 1,2 in r1c5

10. 22(3)n23 = {(58/67)9} (no 1,2,3,4)
10a. -> must have exactly 1 of {56}, which must go in r2c6
10b. -> no 5,6 in r1c6+r2c7
10c. 22(3)n23 and 24(3)n12 form grouped X-Wing on 9 in r12
10d. -> no 9 elsewhere in r12

11. 9 in r1 locked in n2 -> not elsewhere in n2

12. Naked Triple (NT) on {789} at r1c46+r2c4
12a. -> no 7,8,9 elsewhere in n2
12b. Cleanup: no 1,2 in r2c5

13. 9(2)n2 (step 1) now {36/45} = {(3/4)..},{(5/6)..}
13a. -> 9(2)n2 and r2c6 form killer pair on {56}
13b. -> no 5,6 elsewhere in n2

14. Naked Triple (NT) on {789} at r2c347
14a. -> no 7,8 elsewhere in r2 (Note: 9 already eliminated in step 10d)

15. Outies n2: r2c37+r45c5 = 31(5)
15a. 9 of r2 locked in r2c37 = {79/89} = 16 or 17
15b. -> r45c5 = 14 or 15 = {59/68/69/78} (no 1,2,3,4) = {(8/9)..}
15c. -> 9(2)n2 (step 12) and r45c5 together block {57} combo for 12(2)n58
15d. -> 12(2)n58 = {39/48} (no 5,7) = {(3/4)..},{(8/9)..}
15e. -> 9(2)n2 and 12(2)n58 form killer pair on {34} -> no 3,4 elsewhere in c5
15f. 9(2)n2 and r45c5 (step 15b) form killer pair on {89} -> no 8,9 elsewhere in c5

16. {12} in n2 locked in r3 -> not elsewhere in r3

17. Innies r89: r8c37 = 12(2) = {39/48/57} (no 1,2,6)

18. Innies c12: r19c3 = 7(2) = {16/25/34} (no 7,8,9)

19. Innies c89: r19c7 = 5(2) = {14/23} (no 5,6,7,8)

20. Innies c6789: r389c6 = 8(3) = {125/134} (no 6,7,8,9)
20a. -> 1 locked for c6

21. 1 in n5 locked in c3 -> not elsewhere in c3

22. Outies n7: r6c1+r7c4 = 12(2) = {39/48/57/66} (no 1,2)
22a. min. r7c4+r8c3 = {34} = 7
22b. -> max. r7c3 = 6 (no 7,8,9)
22c.

23. Outies n9: r6c9+r7c6 = 11(2) = {29/38/47/56} (no 1)

24. I/O diff. n7: r7c12 = r7c4 + 6
24a. -> no 6 in r7c12 (IOU)

25. I/O diff. n9: r7c89 = r7c6 + 4
25a. -> no 4 in r7c89 (IOU)

26. 18(3)n47 = {279/378/459/468} (no 1)
26a. Note: {189/369/567} all blocked by 14(2)n7 (step 6)

27. 12(3)n7 = {129/138/147/237/246/345}
27a. Note: {156} blocked by 14(2)n7 (step 6)

28. 13(3)n78 can only contain at most 1 of {56789} in n7 (due to no {12} in r7c4)
28a. 14(2)n7 contains exactly 2 of {56789}
28b. 12(3)n7 contains exactly 1 of {56789} (step 27)
28c. -> 18(3)n47 cannot contain two of {56789} in n7
28d. -> r6c1 = {56789} (step 26)
28e. furthermore, 13(3)n78 must now contain exactly 1 of {56789} in n7
28f. -> no 8,9 in r7c4

29. Outies r89: r7c3467 = 16(4)

30. Innies n8: r7c456 = 19(3)

31. Combining steps 29 and 30: r7c5 = r7c37 + 3
31a. -> r7c5 = min. 6
31b. -> r7c5 = {89}, r6c5 = {34}
31c. -> r7c37 sum to 5 or 6
31d. -> no 6,7,8,9 in r7c37

32. Revisit step 30: r7c456 = {379/469/478/568} (no 2)
32a. only 1 of {89}, which must go in r7c5
32b. -> no 8,9 in r7c6
32c. cleanup: no 2,3,9 in r6c9 (step 23)

33. Hidden killer pair on {89} in c6 at r1456c6
33a. r456c6 cannot contain both of {89} due to r45c5 (step 15b)
33b. -> r1c6 = {89} (no 7) r456c6 = {(8/9)..}
33c. -> r45c5 and r456c6 form killer pair on {89} -> no 8,9 elsewhere in n5

34. 7 in n2 locked in r12c4 -> no 7 elsewhere in c4
34a. no 7 in r2c3
34b. cleanup: no 5 in r6c1 (step 22)

35. Outies r789: r6c159 = 16(3) = [637/736/745/835/934]
35a. -> no 8 in r6c9
35b. cleanup: no 3 in r7c6 (step 23)

36. {12} unavailable in r7c4+r8c3
36a. -> no 5 in r7c3 (permutations, 13(3) cage)

37. Innies n78: r7c1256 = 25(4) = {2689/3589/3679/4579/4678}
37a. (Note: cannot be {1789}, because 1 unavailable)
37b. -> must contain 2 of {789}
37c. only other place for {789} in r7 is r7c89
37d. -> r7c1256 and r7c89 form hidden killer triple on {789} in r7
37e. -> r7c89 = {(7/8/9)...}
37f. -> no 5,6 in r7c89; no 7 in r6c9
37g. cleanup: no 4 in r7c6 (step 23)

38. 15(3)n69 = {159/249/258/348/357} (no 6)
38a. Note: {168/267} both blocked by 15(2)n9 (step 8)
38b. cleanup: no 5 in r7c6 (step 23)
38c. from step 35, r6c159 now [745/835/934]
38d. -> no 6 in r6c1
38e. -> no 6 in r7c4 (step 22)

39. Hidden single (HS) in r7 at r7c6 = 6
39a. -> r6c9 = 5 (step 23)
39b. cleanup: no 9 in r6c1 (step 38c) -> no 3 in r7c4 (step 22); no 9 in r8c7 -> no 3 in r8c3 (step 17)

40. Naked single (NS) at r2c6 = 5
40a. cleanup: no 4 in 9(2)n2 (step 1); no 7 in r2c7 (step 10)

41. HS in r2 at r2c4 = 7

42. HS in c5 at r6c5 = 4
42a. -> r7c5 = 8, r6c1 = 7 (step 38c), r7c4 = 5 (step 22)

43. HS in c4 at r1c4 = 8
43a. -> r1c6 = 9; r2c37 = [98]

The rest solves easily now.
Last edited by mhparker on Wed Sep 19, 2007 2:01 pm, edited 1 time in total.
Cheers,
Mike
mhparker
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Post by mhparker »

Para wrote:Just to make it complete. Here is the picture for Assassin 68V3.
Oh yeah, I forgot - we'll need that picture for the Unsolvables list! :-)

P.S. How does one represent DLX in a walkthrough?

P.P.S. I am wondering why Ruud didn't post the pictures himself.
Cheers,
Mike
mhparker
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Post by mhparker »

Hi Cathy,
CathyW wrote:Deleted! An oversight in the prelims had major effect in the rest of the WT. Reworking!!
:roll:
CathyW wrote:V1.5 WT Easier still on the 3rd attempt!!
It must be - the AICs I wanted to check out are gone!! Fortunately, I managed to archive a copy of your 2nd attempt before you deleted it! :)

The chains are very interesting for me. The fact that the grid state on which they are based was reached via a logic flaw is only of secondary importance(!). But, of course, I'm interested in your 3rd attempt, too!

What about the rating? Your third attempt makes the puzzle look easy, but of course a WT doesn't say anything about how much searching/thinking had to be done to solve the puzzle...

P.S. Gary, if you're reading this, rest assured that I haven't forgotten your last question on AICs. I'll post a reply as soon as I can.
Cheers,
Mike
CathyW
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Post by CathyW »

Reinstated "Flawed" WT for 1.5 just in case anyone else want's to check out the potential AICs

I would rate this puzzle as 1.25 - 1.5. As you say the WTs don't really reflect the time and thinking that goes on. It took me a couple of hours on the 1st attempt without trying to keep a WT at the same time (the solution came mostly from nibbling away at the cage combinations). By the time I got to the 3rd attempt I was able to optimise it to some degree.

A68 V1.5

Prelims

a) 17(2) r12c5 = {89} n/e N2/c5
b) 27(4) @ r2c1 = {3789/4689} Must have 8 and 9 -> r56c1 <> 8,9 (see all cells of 27(4))
c) 22(3) N6 = {589/679} 9 n/e N6
d) 6(2) r67c5 = {15/24}
e) 19(3) @ r7c6 and r8c4: no 1
f) 13(2) r89c1 = {49/58/67}
g) 8(3) N7 = {125/134} 1 n/e N7
h) 11(3) r9c456: no 9
i) 10(2) r89c9: no 5


1. Outies c12: r19c3 = 9 = [45/54/63/72/81]

2. Outies c89: r19c7 = 17 = {89} n/e c7
a) NP {89} r1c57 n/e r1 -> r9c3 <> 1 -> 1 locked r89c2 n/e c2
b) r89c8 of 16(3) = (1…7)
c) r7c6 = (89) (because max from r78c7 = 6+7 = 13 thus r7c6 is min 6 but can’t be 6 or 7.) -> r78c7 <> 2
d) 19(3) r8c456: {289}blocked by r7c6 -> r8c456 <> 2

3. KP {89} N8: r7c6 and 19(3) r8c456 = {379/469/478/568} must have at least one of 8,9 -> 11(3) r9c456 <> 8, r7c4 <> 8,9

4. Innies r89: r8c37 = 13 = [67/76/85/94]

5. Outies r789: r6c159 = 15 = [618/258/528/627/726/348/357/753]/{456}

6. Outies N7: r6c1 + r7c4 = 10 = {37/46/55}
-> split 15(3) r6c159 <> [258]

7. Outies N9: r6c9 + r7c6 = 14 = [59/68]
a) split 15(3) = [726]/{456} 6 n/e r6
b) r6c5 <> 1-> r7c5 <> 5
c) r6c1 <> 3 -> r7c4 <> 7
d) KP r9c6 and 22(3) N6: r4c789, r56c7 <> 5,6
e) combo analysis 14(3) @ r9c6: r7c89 <> 4, 9

8. Innies N8: r7c456 = 15 = [519/429/618/528/348]

9. Innies r8: r8c1289 = 13 = 7{123}/{1246/1345}
Clean up: r9c1 <> 4,5; r9c9 <> 1,2,3

10. 16(3) @ r7c3: r7c4+r8c3 is min 3+6 = 9 -> r7c3 is max 7

11. 16(3) @ r1c4: r12c4 is max 6+7 = 13 -> r2c3 is min 3

12. 9 locked r9c79 -> r9c1 <> 9 -> r8c1 <> 4
a) split 13(4) = 7{123}/6{124}/5{134} -> r9c9 <> 4
b) ca 16(3) N9: r9c8 <> 1,2

13. 2 locked to split 13(4) in r8c1289
a) split 13(4) = 7{123}/6{124}
b) 13(2) r89c1 = {67} n/e N7/c1
c) split 15(3) r6c159 = {45}6 -> r6c9 = 6 -> r7c6 = 8 -> {45} n/e r6
d) clean up: r7c5 <> 4; r7c7 <> 3; r7c89 <> 2; r8c9 <> 4
e) 2 locked r8c89 -> r8c2 <> 2
f) 18(3) @ r6c1 = {459} -> 9 locked r7c12 -> r8c3 = 8 -> r7c34 <> 4
g) 22(3) N6 = {589} -> r4c89 <> 8 -> 5 locked r5c89 n/e r5

14. Killer combo N9: r78c7 = {47/56}; r7c89 = {17/35} -> r9c8 <> 5,7; r9c9 <> 7 -> r8c9 <> 3

15. 7 locked rc789 -> r8c7 <> 7 -> r7c7 <> 4
a) -> 4 locked r7c12 -> r6c1 = 5, r6c5 = 4, r7c5 = 2;
b) 8(3) = {125} -> r8c2 = 1, r7c3 = 3, r7c4 = 5, r8c9 = 2, r9c9 = 8, r9c7 = 9, r1c7 = 8, r1c5 = 9, r2c5 = 8
c) r7c89 = {17}, r89c8 = {34} n/e c8 -> r7c7 = 6, r8c7 = 5
d) 19(3) r8c456 = {379/469}
e) 11(3) r9c456 = {137/146}
f) clean up: r1c3 = (47)

16. 5 locked r34c5 (within 21(5)) -> r3c6 <> 5; 21(5) = {12567/23457} Must also have 2 and 7.
a) 2 locked r3c46 n/e N2/r3

17. 8 locked r34c1 -> r4c2 <> 8

18. 27(4) @ r2c1 = {3789/4689}
a) CA -> r4c2 = (67)
b) 9 locked r234c1 -> r7c1 = 4, r7c2 = 9
c) r234c1 = {389} -> r4c2 = 7, r15c1 = {12}
d) 13(3) @ r5c1 = [148/238/283] -> 8 locked r45c2 -> r3c2, r4c1 <> 8 -> r3c1 = 8
e) 6 locked r456c3 -> r23c3 <> 6

19. 7 locked r56c7 -> r23c7 <> 7
a) 12(3) @r5c7 = {147/237} -> r6c6 <> 7,9 -> r56c7 <> 1
b) 1 locked r4c789 n/e r4

20. HS r4c4 = 8

21. 6 locked r45c3 -> r5c4 <> 6
-> 6 locked r45c56 -> r3c6 <> 6

22. 20(5) N1 = {12467/13457/23456} must have 4
-> r23c3 <> 4

23. 19(3) r8c456 = {379/469}
-> CA: r8c46 <> 6

24. 14(3) @ r5c3 = {149/167/239} -> CA r5c3 <> 1, r6c4 <> 1,2

25. Outies r1234: r5c456 = 14 = {167/239} -> r5c46 <> 3
a) KP {12} split 14(3) with r5c1 -> r5c37 <> 2

26. 15(4) @ r2c9 = {1239/1257/1347} must have 1
a) Forms grouped x-wing with r7c89 on 1 -> 30(5) <> 1
b) 30(5) = 8{2569/4567}no 3 and must have 5 -> r1c9 <> 3; r23c9 <> 5
c) 15(4) @ r2c9 = {1239/1347} must have 3
d) CA on 30(5) -> r1c9 <> 7

27. 20(4) @ r3c3 = 8{129/147/156} must have 1
-> CPE r3c4 <> 1

28. 14(3) @ r5c3 = [419/617/923]
a) r6c3 = (12) NP with r5c1 -> r4c3 <> 2
b) 20(4) @ r3c3 = 8[192/147/741/561] -> r3c3, r5c4 <> 9
c) 9 locked r2c13 -> r2c89 <> 9
d) split 14(3) r5c456: r5c6 <> 2

29. Found an AIC (I think): 1s: r5c4 = r3c3 – r6c3 = r6c6 -> r5c56 <> 1
a) HP {12} r5c14
b) split 14(3) = [167/176/239]

30. And another: 1s: r5c4 = r5c1 – r1c1 = r1c46 -> r2c4 <> 1

31. 15(4) @ r2c9 = {1239/1347} -> r3c9 <> 1

32. Innies c1234: r389c4 = 15 =[276/294] -> r3c4 = 2
a) r5c4 = 1, r5c1 = 2, r1c1, r6c3 = 1
b) r56c2 = {38} n/e N4/c2 -> r4c1 = 9, r2c1 = 3
c) r45c3 = {46} -> r19c3 = [72] -> r9c2 = 5
d) r3c3 = 5, r2c3 = 9 -> r12c4 = [34] -> r9c4 = 6, r8c4 = 7, r6c4 = 9 -> r5c3 = 4, r4c3 = 6

All singles from here.
Para
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Post by Para »

mhparker wrote: Who's this "Ed" guy? Reminds me of someone I used to know around here... :wink:
Back in the old days, he used to solve puzzles. Nowadays he's so occupied with determining difficulty of puzzles, by the time he actually gets to solving a puzzle, he'll have forgotten how to do it. But we can help him with the basics. I'm sure with some coaching he'll get the hang of it.

Para
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Post by Para »

CathyW wrote:V1.5 WT Easier still on the 3rd attempt!!
Maybe try it another 10 times :wink: (or you could just go ahead with Ruud's V2 for a change).

Para
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assassin 68 v1.5

Post by gary w »

Using the same prelims as Cathy details;

r7c4<>1 > 9@r6c1 then cannot put 9 in 27/4 cage.
IF (!!??) 1 is @ r7c5 >r6c5=5 >r6c9=6 >>r7c6=8 and r6c1=4 >r7c4=6 >r7c12=5/9 so can't complete the 14/3 cage at N6/9.

Thus 1 goes in the 11/3 cage N8 > 1 @ r8c2.

Although still a bit tough this breaks the puzzle.
Having done all the prelims I saw this quite easily.No pencil marks or "guessing".

What I'ld like your opinion on is;how far does a hypothetical (doesn't sound too bad) have to extend before it becomes T and E (ugh!)?

From step 1? Only if you need pencil marks to reach a contradiction?I rather like solving them this way (when I can !) rather than ..how can I put this?....the use of the apparently tortuous numbers of combos that the experts use.I can see why this method doesn't appeal to the logical or aesthetic sense but at least I can solve them and still leave a LITTLE of the day over to do other things!!
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Post by CathyW »

Para wrote:
CathyW wrote:V1.5 WT Easier still on the 3rd attempt!!
Maybe try it another 10 times :wink: (or you could just go ahead with Ruud's V2 for a change).

Para
No thanks! I'd prefer a different cage pattern now so will await the A69 on Friday and leave the harder versions of A68 for others.

To answer Gary's question about hypotheticals vs T&E:
to a certain extent it's up to the individual to decide what constitutes acceptable methods. My personal preference is to get as much as possible from 45 rules - innies, outies and innie/outie differences - first, 2nd look for locked candidates, pointing cells to make eliminations, 3rd examine combinations for possible killer pairs, restricted, blocked and conflicting combinations, and revisit the split combinations as required. I don't rule out hypotheticals in harder puzzles but wouldn't look for them from the outset.

The main thing is to enjoy doing the puzzles. :)
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Post by sudokuEd »

mhparker wrote: Who's this "Ed" guy?
Para wrote:Nowadays he's so occupied with determining difficulty of puzzles, by the time he actually gets to solving a puzzle, he'll have forgotten how to do it. ...I'm sure with some coaching he'll get the hang of it.
:D You guys are fantastic - make great Aussies. Thanks for the warm re-welcome!

And congratulations to you both on solving 68V2 8-) . Will keep trying without coaching for a few more sessions.

Cheers
Ed
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assassin 68 v2

Post by gary w »

Mike,

Awestruck by your wt.
Just a couple of questions both regarding the same cell..

Step 37c > imply r7c7 <>789.Why not? and similarly
Step 39 > imply r7c7 <>6.Again I can't see why not.Obviously missing something pretty straightforward.

Many thanks

Gary :?
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