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 Assassin 71 Goto page 1, 2  Next
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CathyW
Master

Joined: 31 Jan 2007
Posts: 161
Location: Hertfordshire, UK

 Posted: Fri Oct 05, 2007 2:29 pm    Post subject: Assassin 71 No, I haven't solved it yet! But the fact that no-one else has either shows either it's really difficult or you haven't had time yet. I'll have another look at it this evening. Edit: This is definitely a tough one. 45 steps (about 3 hours) and counting. I have c7 fixed and a few other placements and thought it would start falling into place but there's still work to do! Edit 2: Finally! Took about 4 hours in total. At least 1.5 rating. I can't say I particularly want to go through it again so if there's any corrections required, I'll just take your word for it. Prelims a) 14(4) @ r1c7 and r8c3: no 9 b) 12(3) r34c3 = {39/48/57} c) 10(2) @ r3c4 and r3c6: no 5 d) 19(3) @ r3c5: no 1 e) 13(2) @ r3c7 and r6c6 = {49/58/67} f) 8(2) @ r5c3 and r5c6 = {17/26/35} g) 27(4) @ r4c8 = {3789/4689/5679} -> 9 not elsewhere in N6 -> r3c7 <> 4 h) 9(2) r67c3: no 9 i) 11(2) r67c4 and r67c5: no 1 j) 5(2) r67c7 = {14/23} 1. Innies r12: r2c18 = 12 = {39/48/57} 2. Innies r89: r8c29 = 8 = {17/26/35} 3. Outies c12: r29c3 = 10 = {19/28/37/46} -> r158c3 = 14 4. Outies c89: r18c7 = 7 = {16/25} ({34} blocked by 5(2)) a) KP with 5(2) -> 1,2 not elsewhere in c7 -> r5c6 <> 6,7 b) r259c7 = 20 = {389/479/578} ({569} blocked by 13(2) -> r259c7 <> 6 -> r5c6 <> 2 5. Innies r6789: r6c29 = 15 = {69/78} 6. Outies c1234: r29c5 = 7 = {16/25/34} 7. Outies c6789: r18c5 = 8 = {17/26/35} 8. O-I N1: r4c23 – r1c3 = 7 -> r4c2 <> 7 9. O-I N3: r2c7 – r4c79 = 1 a) r4c79 max 8 -> r4c7 = (4567), r4c9 = (123) -> r3c7 <> 5 b) r2c7 min 6 -> r2c7 = (789) 10. O-I N7: r6c13 – r8c3 = 5 -> r6c1 <> 5 11. O-I N9: r9c7 – r6c78 = 1 a) r6c78 is max 8 -> r6c8 <> 8 b) 8 locked to 27(4) in N6 = {3789/4689} (eliminate 5) 12. O-I r1234: r4c18 – r5c5 = 2 -> r4c1 <> 9 13. Innies N69: r4c9 + r459c6 = 19 a) 5(2) r67c7 must have one of 3,4 b) split 19(4) must have one of 3,4 within r459c6 -> split 19(4) <> {1567} 14. 27(4) N6 must have one of 3,4 a) From step 9, O-I N3 <> [843] 15. Split 19(4) = 1[639/738/459], 2[539/638/458], 3{57}4 -> r9c7 <> 5,7 16. Split 20(3) r259c7 = [839/938/974/758] 17. 27(4) N6 must have one of 3,6 a) Split 19(4) can’t have both 3,6 within N6 -> 19(4) <> [1639/2638] b) r4c7 <> 6, r3c7 <> 7 18. Killer combo N6: 27(4) must have one of 3,4; split 19(4) must have one of 3,4 within N6 a) r6c78 <> 3,4 -> r7c7 <> 1,2 b) 21(4) N9 and 18(4) @ r6c8 can’t have both 3,4 c) 16(4) @r6c1 can’t have both 3,4 within r7c12 19. Innies N36: r256c7 + r6c8 = 19 a) Can’t have both 3,6 in N6 because of 27(4) -> {1369/2368} blocked. b) Options for split 19(4) = {1279/1378/1567/2359/2377} 20. Innies N14: r6c1 + r156c3 = 19 -> can’t have both 1,2 within r6c13 21. Innies N47: r4c2 + r458c3 = 21 22. Innies r1234: r34c5 + r4c18 = 21 23. Conflicting combo: Split 19(4) r256c7, r6c8 <> [7516] since would block both options for split 7(2) r18c7 a) r5c7 <> 5 -> r5c6 <> 3 b) r6c8 <> 6 24. 27(4) N6 = {4689}(only available combo since r5c7 = (37)) -> r4c7 <> 4 -> r3c7 <> 9 a) Clean up: r6c2 <> 8 25. 4 locked r79c7 n/e N9 26. Split 20(3) r259c7 = [839/938/974] -> r2c7 <> 7 a) 7 locked r45c7 -> r6c8 <> 7 b) Split 19(4) r4c9 + r569c7 must have 7 = [1738/3574] -> r9c7 <> 9 27. HS r2c7 = 9 a) split 12(2): r2c18 <> 3 b) split 10(2) r29c3: r9c3 <> 1 c) r4c79 = [53/71] -> 2 locked r6c78 n/e r6 -> clean up: r7c45 <> 9, r7c3 <> 7 28: r4c79 = [53/71], r5c67 = [17/53] a) r4c6 <> 1 -> r3c6 <> 9 b) r4c5 <> 5 c) r4c4 <> 1 -> r3c4 <> 9 29. 9 locked r789c6 -> r46c6 <> 9 -> r7c6 <> 4; r3c6 <> 1 30. 1 locked r5c46 -> r5c123 <> 1 -> r5c4 <> 7 31. Conflicting combo N6: a) r4c9 = 1 -> r4c7 = 7, r5c7 = 3 -> Conflict for 5(2) b) Therefore: r4c9 = 3 -> r4c7 = 5, r5c7 = 7, r5c6 = 1, r3c7 = 8, r9c7 = 4, r7c7 = 3, r6c7 = 2, r6c8 = 1 c) Clean up: r2c1 <> 4, r3c46 <> 7, r4c46 <> 2, r6c45 <> 8, r6c3 <> 6, r7c3 <> 8, r3c3 <> 7,9, r4c3 <> 4, 32. HS r1c8 = 3 33. 14(4) N3 = {1346} only possible combo, -> r2c8 = (57), r3c89 = (257) a) 2 locked r3c89 n/e r3 b) Clean up: r4c46 <> 8 c) 4 locked r45c8 -> r5c9 <> 4 d) Split 12(2) r2c18 = {57} n/e r2 34. 10(2) r34c6 = [37]/{46} -> KP 13(2) r67c6 <> {67} 35. 1 locked r7c123 n/e N7 36. Split 8(2) r8c29 = {26} only possible combo -> n/e r8 a) r8c7 = 1 -> r1c7 = 6 b) 25(4) N7 <> {2689} -> r9c123 <> 2 c) 2 locked r9c456 -> r7c45 <> 2 -> r6c45 <> 9 37. 1 locked r4c12 -> r3c1 <> 1 38. Grouped Turbot (5): r2c1 = r2c8 – r89c8 = r9c9 -> r9c1 <> 5 39. 9 locked to 19(3) r345c5 = {289/379/469} 40. 5 locked r1c456 -> r1c123 <> 5 41. Split 8(2) r18c5 = [17/53] 42. 14(4) @ r8c3 = {1238/1247/1346/2345} Must have one of 3,7 a) Since r8c5 = (37), r8c6 <> 3,7 43. Grouped Turbot (9): r3c12 = r3c5 – r45c5 = r4c4 -> r4c2 <> 9 44. Split 10(2) r29c3 = [19/28/37/46] 45. Split 7(2) r29c5 = [16/25/43/61] 46. Pointing cells: 6 locked r2c2, r3c12 -> r4c2 <> 6 47. 14(4) @ r8c3 must have 1 within r9c45 -> {2345} blocked -> 14(4) <> 5 a) clean up: r2c5 <> 2 48. 2 locked r45c5 n/e N5 – r5c3 <> 6 a) 19(3) r345c5 = 9{28} b) 11(2) r67c5 <> [38] c) 13(2) r67c6 <> [85] 49. HS r4c4 = 9 -> r3c4 = 1, r1c5 = 5, r8c5 = 3 50. 11(2) r67c5 = {47} -> r2c5 = 6, r9c5 = 1 51. r12c6 of 20(4) = {24} n/e N2 -> r3c6 = 3, r4c6 = 7, … All singles from here. Last edited by CathyW on Sun Oct 14, 2007 6:57 pm; edited 2 times in total
gary w

Joined: 07 Sep 2007
Posts: 84
Location: south wales

 Posted: Sat Oct 06, 2007 12:01 am    Post subject: assassin 71 Cathy said this was a tough one..sure was..took me 5 hrs plus Like Cathy I found that with combination work on nonets 3/6/9 it was not too long before c7 was pretty much sorted.But then round 2 began..another lenghty period before any more placements made. Just a couple of points on the wt Cathy.. 15. I think it should be r9c 7 <>5,7? 38/43 the grouped turbots.I don't understand the nomenclature here.for you cannot be referring to the numbers in the cells eg r2c1 (which turned out to be a 7) you say = r2c8 (a 5) - r78c8 (an 8,7).Obviously as an equation this doen't make sense so I wonder what you mean by the equalities?? Edit.. excuse my ignorance.Just looked up turbots on another site and can now see what the "equations2 mean..they're linkages not equations.Right! Very hard to spot though.I'm impressed! It was very difficult..well done!! Surely v2 won't be harder?? [
Ruud
Site Owner

Joined: 30 Dec 2005
Posts: 601

Posted: Sat Oct 06, 2007 9:45 am    Post subject:

 gary w wrote: Surely v2 won't be harder??

hehehe...

Introducing:

Assassin 71 (V2) - Full Border

3x3::k:4608:4608:4354:4354:6404:6404:4358:4358:4358:4617:4608:4608:4354:4354:6404:6404:5648:4358:4617:4617:2580:3349:2326:2583:3864:5648:5648:5915:4617:2580:3349:2326:2583:3864:5154:5648:5915:5915:3366:3366:2326:809:809:5154:5154:4653:5915:2863:3376:1585:1586:3891:5940:5154:4653:4653:2863:3376:1585:1586:3891:5940:5940:4927:4653:5953:5953:5955:5955:3909:3909:5940:4927:4927:4927:5953:5953:5955:5955:3909:3909:

The initial candidates in the border look very promising. This puzzle could be a nice addition to the unsolvables list.

Ruud
_________________
“If the human brain were so simple that we could understand it, we would be so simple that we couldn't.” - Emerson M Pugh
CathyW
Master

Joined: 31 Jan 2007
Posts: 161
Location: Hertfordshire, UK

 Posted: Sat Oct 06, 2007 10:18 am    Post subject: Thanks for the comments Gary. Finding the strong and weak links is the key to spotting the Grouped Turbots - on paper I use coloured pencils to mark my grid to help with identifying the strong links. Sometimes I use JSudoku afterwards to check through my steps - that has a facility to highlight strong links which can be helpful. Colouring is one of my favourite techniques in "vanilla" sudoku too. I'll leave the V2 for the serious masochists - Richard's solver took 139 steps! Whether it is solvable on paper is another matter.
Afmob
Expert

Joined: 22 Sep 2007
Posts: 103
Location: MV, Germany

 Posted: Sat Oct 06, 2007 5:16 pm    Post subject: What a monster. I didn't find a nice way to solve to puzzle so be prepared for some contradiction moves. I think it was more difficult than A69 V1.5 so I guess rating is about 1.75. Assassin 71 Walkthrough: 1. R6789 a) Innies R89 = 8(2) -> no 4,8,9 b) Innies R6789 = 15(2) = {69/78} 2. R12 a) Innies R12 = 12(2) -> no 1,2,6 3. C1234 a) Outies C12 = 10(2) -> no 5 b) Outies C1234 = 7(2) -> no 7,8,9 4. C6789 a) Outies C89 = 7(2) -> no 7,8,9 b) Innies C789 = 20(3) -> no 1,2 c) Innies C789 = 20(3) -> R29C7 <> 3 because R5C7 <= 7 d) 8(2) @ N6: R5C6 <> 6,7 e) Outies C6789 = 8(2) -> no 4,8,9 f) 27(4) = 9{378/468/567} -> 9 locked for N6 g) 13(2) @ N3: R3C7 <> 4 5. N3 a) Innies+Outies: -14 = R4C9 - R23C7 -> R23C7 = 15/16/17 -> R23C7 <> 4,5 -> R4C9 = (123) b) 13(2): R4C7 <> 8 6. N69 a) Innies+Outies N9: -1 = R6C78 - R9C7; R9C7 = (456789) -> R6C78 = 3/4/5/6/7/8 -> R6C8 <> 8 b) 8,9 locked in 27(4) = 89{37/46} -> no 5 7. C789 a) Outies C89 = 7(2): {34} blocked by Killer pair (34) of 5(2) b) Innies C789 = 20(3) <> 6 since {569} blocked by Killer pair (56) of Outies of C89 c) 8(2) @ N6 = [17/35/53] 8. C5 a) Innies = 15(4) = 7(2) + 8(2) (see 3b,4e) = 1{257/347/356} because 7(2), 8(2) <> 8,9 and 19(3), 11(2) <> 1 -> Outies C6789 = 8(2) = {17/35} b) 19(3) <> 3 because {379} blocked by Killer pair (37) of Innies 9. C123 a) Outies 10(2) <> {37} because if 10(2) = {37} -> 12(2) = {48} -> no combination for 9(2) 10. C7+N6 a) 13(2): R4C7 <> 6 because if 13(2) = {67} -> Innies 20(3) = {389} -> R5C7 = 3 -> R4C7 <> 6 (Killer pair (36) of 27(4)) b) 13(2): R3C7 <> 7 c) Consider position of 6 in N6: Either 27(4) = {4689} or R6C8 = 6 -> R6C8 <> 4 d) R9C7 <> 5 -> 20(3) = [875] -> 13(2) = [94] -> R45C7 = [47] -> blocks both combos of 27(4) 11. C7+N69 ! a) Innies N69 = 19(3+1) = R9C7 + R45C7 + R4C9; R9C7 <> 9 because: If R9C7 = 9 -> R45C7 + R4C9 = 10(3) = {127/235/145} - i. <> {127} because R45C7 has no 1,2 - ii. <> {235} -> R4C7 = 5, R5C7 = 3 -> Innies of C7 would be {389} - but is impossible because of 13(2) = [85] - iii. <> {145} R5C7 = 5 -> 13(2) = [94] -> not possible because R9C7 = 9 -> R9C7 <> 9 b) 9 locked in R23C7 for N3 c) Innies R12: R2C1 <> 3 d) Innies+Outies N9: -1 = R6C78 - R9C7; R9C7 = (478) -> R6C78 = 3/6/7 -> R6C8 <> 7, R6C7 <> 3 (3 + ? = 3/6/7) e) 5(2): R7C7 <> 2 f) Innies N69 = 19(3+1): R5C7 <> 5 because If R5C7 = 5 -> Innies C7 = 20(3) = {578}, Innies N69 = 14(2+1) = R4C79 + R9C7 = {24+8/34+7}: - i. 34+7 blocked by Killer pair (34) of 27(4) - ii. 24+7 -> R4C79 = [42] -> R6C1 = 1 -> 5(2) = [14] -> 2 4's in C7 -> R5C7 <> 5 g) 8(2) = [17/53] 12. C7+N6 a) 9 locked in Innies = 20(3) = 9[38/74] -> R2C7 = 9, R9C7 <> 7 b) 13(2) = [67/85], XOuties C12: R9C3 <> 1 c) 7 locked in R45C7 for N6 d) 27(4) = {4689} locked e) 4 locked in R79C7 for N9 f) Innies R12 = 12(2) = {48/57} 13. N36 a) Innies+Outies N3: -14 = R4C9 - R23C7, R2C7 = 9, R3C7 = (68) -> R4C9 = (13) b) 2 locked in R6C78 for R6 c) 11(2) @ C5: R7C5 <> 9, 11(2) @ C4: R7C4 <> 9, 9(2) @ C3: R7C3 <> 7 14. C6 a) 9 locked in R789C6 b) 10(2) <> 1, 13(2): R7C6 <> 4 15. N369 ! a) Innies N36 = 10(3): R6C8 <> 3 because R5C7 would be 7 b) ! Innies+Outies N9: -1 = R6C78 - R9C7; R9C7 = (48) -> R6C78 = 3/7 = {12/25} But if R6C7 = 1 then R6C78 must be [12] -> R7C7 = 4 = R9C7 -> R6C7 <> 1 c) R6C7 = 2, R7C7 = 3, R5C7 = 7, R5C6 = 1, R4C7 = 5, R3C7 = 8, R9C7 = 4 d) R6C8 = 1, R4C9 = 3 e) Hidden Single: R1C8 = 3 @ C8 f) 14(4) = 3{146} locked in N3 because R1C7 = (16) g) 4 locked in R12C9 for C9 16. R3 a) 2 locked in R3C89 b) 12(2) = [39/48/57], 10(2) @ C4 = [19/37/46/64], 10(2) @ C6 = [37/46/64] 17. N9 a) 18(4) = 12{69/78} -> 2 locked 18. R7 a) 1 locked in R7C123 for N7 b) 9(2): R6C3 <> 6, R6C4 <> 8; 11(2) @ C4: R6C4 <> 8; 11(2) @ C5: R6C5 <> 8 19. C6789 a) 13(2) <> 6,7 which is blocked by Killer pair (67) of 10(2) b) Outies C6789 = 8(2) = [17/53/71] 20. R12 a) Innies 12(2) = {57} locked for R2 b) 20(4): R1C5 <> 7 since R1C6 <> 1,3 c) 20(4) = 9{128/137/146/245} -> has 1 xor 5 -> R1C6 <> 5 because R5C1 = (15) 21. C1234 a) Outies C12 = 10(2) = [19/28/46/82] b) Outies C1234 = 7(2) = [16/25/43/61] 22. R89 a) Innies = 8(2) = {26} locked for R8 b) R8C7 = 1, R1C7 = 6 c) 25(2) <> 2 since {2689} is blocked by R8C2 = (26) d) Outies C12 = 10(2) = [19/28/46] e) 2 locked in R9C46 for N8 f) 11(2) @ C4: R6C4 <> 9, 11(2) @ C5: R6C5 <> 9 23. C5 a) 9 locked in 19(3) -> no 5,7 24. R12 a) 5,7 locked in R1C456 b) 7 locked in 19(4) -> R4C2 <> 7 c) 21(4) must have 3 or 6 -> only possible @ R2C2 -> R2C2 = (36) d) 8 locked in R1C123 for R1 e) 21(4) = 9{138/246} -> 9 locked for R1 and N1 f) Hidden Single: R4C4 = 9 @ C4 g) R3C4 = 1, R1C5 = 5 25. C12345 a) Hidden Single: R9C5 = 1 @ C5, R9C3 = 9 @ C3, R3C5 = 9 @ N2 b) Outies C1234 = 7(2) = [61] -> R2C5 = 6 c) R2C2 = 3 d) Naked quad (2478) locked in N2 e) R3C6 = 3 -> R4C6 = 7, R4C3 = 8, R3C3 = 4 f) Hidden Single: R1C4 = 7 @ N2 g) 19(4) = {1567} -> R4C2 = 1 h) 23(4) = {2678} -> R1C3 = 2, R2C4 = 8 26. Rest is clean-up and singles. Don't want to think about taking on the V2 right now since V1 was so relentless.Last edited by Afmob on Sun Oct 14, 2007 10:01 am; edited 1 time in total
mhparker
Grandmaster

Joined: 20 Jan 2007
Posts: 345
Location: Germany

Posted: Sat Oct 06, 2007 7:46 pm    Post subject:

Hi folks,

 Ruud wrote: The initial candidates in the border look very promising.

Don't they just?!

Maybe we should do this as a team tag solution?

To get the show in motion, here are my first 20 steps. I'd welcome it if anyone else could take over and add a few more.

Assassin 71 V2 Tag Walkthrough

Preliminaries:

10(2)n14 and 10(2)n25 = {19/28/37/46}: no 5
13(2)n25, 13(2)n45 and 13(2)n58 = {49/58/67}: no 1..3
9(3)n25 = {126/135/234}: no 7,8,9
15(2)n36 and 15(2)n69 = {69/78}: no 1..5
3(2)n56 = {12}, locked for r5
11(2)n47 = {29/38/47/56}: no 1
6(2)c5 and 6(2)c6 = {15/24}: no 3,6,7..9

1. 15(2)n36 and 15(2)n69 form Naked Quad on {6789} in c7 -> no 6..9 elsewhere in c7

2. r5c6 and r67c6 form killer pair on {12} in c6 -> no 1,2 elsewhere in c6
2a. cleanup: no 8,9 in r34c6
2b. 10(2)n25 = {37/46}

3. Outies c12: r29c3 = 6(2) = {15/24}: no 3,6,7..9

4. Outies c89: r18c7 = 7(2) = {25/34} (no 1)

5. Innies r12: r2c18 = 13(2) = {49/58/67}: no 1..3

6. Innies r89: r8c29 = 10(2) = {19/28/37/46}: no 5

7. Innies c123: r158c3 = 18(3) = {189/279/369/378/459/468/567} (no eliminations yet)

8. Innies c789: r259c7 = 8(3) = {1(25/34)} (no eliminations yet)

9. Outies c1234: r29c5 = 16(2) = {79}, locked for c5

10. Outies c6789: r18c5 = 14(2) = {68}, locked for c5
10a. 9(3)n25 = {135/234}

11. Innies r6789: r6c29 = 8(2) = {17/26/35}: no 4,8,9

12. r4c5+r56c56 forms Naked Quint on {1..5} in n5 -> no 1..5 elsewhere in n5
12a. cleanup: no 8,9 in r37c4 and r5c3; no 6,7 in r3c6
12b. 3 in n5 locked in 9(3) within r45c5 -> no 3 in r3c5

13. {89} in n5 locked in c4 -> not elsewhere in c4

14. r1289c4 must contain all 3 of {123}
14a. 23(4)n78 cannot contain 2 of {123}, otherwise cage sum unreachable
14b. -> r12c4 must contain 2 of {123}, r89c4 contains 1 of {123} + 1 of {4..7}
14c. -> both of r12c4 = {123} (no 4..9)
14d. 17(4) must contain 2 of {123} (in r12c4)
14e. -> {1457} and {2456} both blocked
14f. must contain 1 of {79} (on r2c5)
14g. -> {1268}, {1358}, and {2348} all blocked
14h. -> poss. combos are: {1259/1349/1367/2357}
14i. -> r1c3 = {456}

15. Innies c123 (step 7): max. r15c3 = 13 -> min. r8c3 = 5
15a. -> no 1..4 in r8c3

16. 8 in n2 locked in 25(4)n23 = {8..} = {2689/3589/4678} (no 1) = {(7/9)..}
(Note: {1789} combo blocked by r2c5)
16a. if {4678}, 4 must go in r2c7
16b. -> no 4 in r12c6
16c. 25(4) and r2c5 form killer pair on {79} within n2
16d. -> no 7 in r3c4
16e. cleanup: no 6 in r4c4

17. 4 in n2 locked in r3 -> not elsewhere in r3
17a. cleanup: no 6 in r4c3

18. I/O diff. n1: r13c3 = r4c2 + 9
18a. min. r4c2 = 1 -> min. r13c3 = 10
18b. -> no 1..3 in r3c3
18c. cleanup: no 7..9 in r4c3
18d. max. r13c3 = 15 -> max. r4c2 = 6
18e. -> no 7..9 in r4c2

19. I/O diff. n3: r23c7 = r4c9 + 6
19a. max. r23c7 = 14 -> max. r4c9 = 8
19b. -> no 9 in r4c9

20. I/O diff. n9: r79c7 = r6c8 + 7
20a. max. r79c7 = 14 -> max. r6c8 = 7
20b. -> no 8,9 in r6c8

Marks pic after step 20:

 Code: .-----------------------.-----------------------.-----------------------.-----------------------------------. | 123456789   123456789 | 456         123       | 68          356789    | 2345        123456789   123456789 | :-----------.           '-----------.           '-----------.           '-----------.-----------.           | | 456789    | 123456789   1245      | 123         79        | 356789      2345      | 456789    | 123456789 | |           '-----------.-----------+-----------.-----------+-----------.-----------:           '-----------: | 12356789    12356789  | 6789      | 456       | 1245      | 34        | 6789      | 12356789    12356789  | :-----------.           |           |           |           |           |           :-----------.           | | 123456789 | 123456    | 1234      | 789       | 12345     | 67        | 6789      | 123456789 | 12345678  | |           '-----------+-----------'-----------:           :-----------'-----------:           '-----------: | 3456789     3456789   | 4567        6789      | 345       | 12          12        | 3456789     3456789   | :-----------.           :-----------.-----------+-----------+-----------.-----------+-----------.           | | 123456789 | 123567    | 23456789  | 6789      | 1245      | 1245      | 6789      | 1234567   | 123567    | |           '-----------:           |           |           |           |           |           '-----------: | 123456789   123456789 | 23456789  | 4567      | 1245      | 1245      | 6789      | 123456789   123456789 | :-----------.           :-----------'-----------+-----------'-----------+-----------'-----------.           | | 123456789 | 12346789  | 56789       1234567   | 68          3456789   | 2345        123456789 | 12346789  | |           '-----------'-----------.           '-----------.           '-----------.           '-----------: | 123456789   123456789   1245      | 1234567     79        | 3456789     12345     | 123456789   123456789 | '-----------------------------------'-----------------------'-----------------------'-----------------------'

_________________
Cheers,
Mike

Last edited by mhparker on Sat Oct 20, 2007 8:12 pm; edited 1 time in total
Andrew
Grandmaster

Joined: 11 Aug 2006
Posts: 300
Location: Lethbridge, Alberta

 Posted: Sun Oct 07, 2007 2:07 am    Post subject: Don't know if I'm going to be able to take much part in this. I still haven't finished A71. From what Mike has posted so far, the early moves are easier, meaning they provide more progress, that the early ones for A71. Anyway here are a couple more steps; I hope nobody objects that I've used normal text rather than Mike's slightly smaller text. 21. I/O diff. n1: r4c23 = r1c3 + 1 21a. IOU no 1 in r4c2 22. I/O diff. N7: r6c13 = r8c3 + 3 22a. IOU no 3 in r6c1 The IOUs on the other two corner nonets have already been done by Mike's I/O steps.
Andrew
Grandmaster

Joined: 11 Aug 2006
Posts: 300
Location: Lethbridge, Alberta

 Posted: Sun Oct 07, 2007 5:22 am    Post subject: And a few more moves 23. Innies c6: r12589c6 = 29 = {15689/23789/24689} (cannot be {14789/25679/34589} which clash with r67c6, cannot be {34679/35678} which clash with r34c6) No point in doing a similar one for c4; that would just repeat what is already known from step 14 and the two 13(2) cages. Also, to complete step 15 15b. r158c3 = {459/468/567} 24. r158c3 = {468/567} (cannot be {459} which clashes with r29c3) 24a. -> no 9 in r8c3 24b. 6 locked in r158c3, not elsewhere in c3 24c. cleanup: no 4 in r4c3, no 5 in r67c3 25. Killer pair 4,5 in r158c3 and r29c3, not elsewhere in c3 25a. cleanup: no 7 in r67c3 It still seems easier than A71. It's already got further than I've reached with A71 where I haven't yet managed anything in c3. I'm going to have to drop out of the "tag" now and stop reading this thread. Otherwise I risk not being able to solve A71 myself; not sure at the moment if I can anyway. I hope that someone else will pick up the "tag" and work with Mike on it!
mhparker
Grandmaster

Joined: 20 Jan 2007
Posts: 345
Location: Germany

Posted: Sun Oct 07, 2007 8:52 am    Post subject:

Thanks, Andrew.

Carrying on...

Assassin 71 V2 Tag Walkthrough (continued)

26. 11(2)n47 = {29/38} = {(2/8)..}
26a. -> {28} combo blocked for 10(2)n14
26b. 10(3)n14 = [73/91]

[Note: last 2 steps could have been done more directly as follows:
25/26. Hidden killer pair on {39} in c3 (i.e., {39} in c3 locked within 10(2) and 11(2) cages)
25/26a. neither cage can contain both of {39}, so each must contain exactly 1 of {39}
25/26b. -> 10(2) = {(3/9)..}, 10(2) = {(3/9)..}
25/26c. -> 10(2) = [73/91], 11(2) = {29/38}]

27. From step 14h, 17(4)n12 = {1259/1349/1367/2357} = {(3/9)..}
27a. -> {39} only available in 17(4)n12 within n2
27b. -> 25(4)n23 cannot contain both of {39} within n2
27c. from step 16, poss. combos for 25(4)n23 are {2689/3589/4678}
27d. -> (from step 27b) if 25(4)n23 = {3589}, 3 must go in r2c7
27e. -> no 3 in r12c6, no 5 in r2c7

28. Innies c789 (step 8) = r259c7 = [215/314/413]
28a. -> no 2 in r5c7; no 1,2 in r9c7

29. Naked single (NS) at r5c7 = 1
29a. -> r5c6 = 2
29b. Cleanup: no 4 in r67c6, no 4 in r37c5

30. Naked pair (NP) on {15} at r67c6 -> no 5 elsewhere in c6 (1 already gone)

31. 5 in n2 locked in r3 -> not elsewhere in r3

32. 5 no longer available to 25(4)n23 (step 27c)
32a. -> 25(4)n23 = {2689/4678} (no 3)
32b. 6 locked within r1c56+r2c6 for n2
32c. cleanup: no 7 in r4c4

33. Innies c789 (step 28) = r259c7 = [215/413]
33a. -> no 4 in r9c7

34. {12} unavailable to 23(4)n89, 8 locked
34a. -> 23(4)n89 = {3578/4568} (no 9)
34b. 5 locked
34c. -> r9c7 = 5
34d. -> r2c7 = 2 (step 33)

35. Hidden single (HS) in n8 at r9c5 = 9
35a. -> r2c5 = 7

Looks like things are going to be pretty straightforward from here on.

Marks pic after step 35:

 Code: .-----------------------.-----------------------.-----------------------.-----------------------------------. | 123456789   123456789 | 456         123       | 68          689       | 34          13456789    13456789  | :-----------.           '-----------.           '-----------.           '-----------.-----------.           | | 45689     | 1345689     145       | 13          7         | 689         2         | 45689     | 1345689   | |           '-----------.-----------+-----------.-----------+-----------.-----------:           '-----------: | 1236789     1236789   | 79        | 45        | 125       | 34        | 6789      | 136789      136789    | :-----------.           |           |           |           |           |           :-----------.           | | 123456789 | 23456     | 13        | 89        | 1345      | 67        | 6789      | 23456789  | 2345678   | |           '-----------+-----------'-----------:           :-----------'-----------:           '-----------: | 3456789     3456789   | 4567        6789      | 345       | 2           1         | 3456789     3456789   | :-----------.           :-----------.-----------+-----------+-----------.-----------+-----------.           | | 12456789  | 123567    | 2389      | 6789      | 145       | 15        | 6789      | 234567    | 23567     | |           '-----------:           |           |           |           |           |           '-----------: | 123456789   123456789 | 2389      | 4567      | 125       | 15        | 6789      | 12346789    12346789  | :-----------.           :-----------'-----------+-----------'-----------+-----------'-----------.           | | 123456789 | 12346789  | 5678        1234567   | 68          34678     | 34          12346789  | 12346789  | |           '-----------'-----------.           '-----------.           '-----------.           '-----------: | 1234678     1234678     124       | 123467      9         | 34678       5         | 1234678     1234678   | '-----------------------------------'-----------------------'-----------------------'-----------------------'

_________________
Cheers,
Mike
mhparker
Grandmaster

Joined: 20 Jan 2007
Posts: 345
Location: Germany

 Posted: Sun Oct 07, 2007 1:50 pm    Post subject: Assassin 71 V2 Tag Walkthrough (final episode) 36. 17(4)n12 = [5237/6137/6317] 36a. -> no 4 in r1c3 36b. 3 locked in r12c4 -> not elsewhere in c4 and n2 37. 10(2)n25 = [46] 37a. cleanup: no 7 in r5c3 and r7c4, no 9 in r3c7 38. r34c4 = [58] 38a. cleanup: no 7 in r3c7, no 5 in r5c3 39. HS in n2 at r1c5 = 6 39a. -> r8c5 = 8 40. NS at r1c3 = 5 40a. -> r12c4 = [23] (step 36), r58c3 = [67] (step 24) 40b. -> r5c4 = 7 41. r34c3 = [91]; r29c3 = [42]; r67c4 = [94]; r89c6 = [37]; r18c7 = [34] 41a. cleanup: no 6 in r7c7 42. NS at r3c5 = 1 43. r67c5 = [42] 44. r67c6 = [15] (hidden singles n58) 45. HS in r8/n7 at r8c1 = 5 46. Split 14(3) at r1c12+r2c2 = {167} (only remaining combo) 46a. -> r2c2 = 6 46b. r1c12 = {17}, locked for r1 and n1 47. r2c1 = 8 47a. -> r12c6 = [89] 47b. -> r2c89 = [51] 48. r3c12 = {23} = 5 total 48a. -> r4c2 = 5 (cage split, but could also be obtained by I/O diff. n1 (step 18)) 48b. -> r45c5 = [35] 49. HS in r9/c6/n6 at r6c9 = 5 50. 9 of n9 locked in 18(4)n47 = {1269} (no 3,7,8) (last remaining combo) 50a. -> r67c1 = [26] 50b. r78c2 = {19}, locked for c2 and n7 51. r13c12 = [1732]; r6c23 = [38]; r7c3 = 3; r9c12 = [48]; r5c12 = [94]; r4c1 = 7 51a. cleanup: no 7 in r7c7 All singles and one cage sum from here. Solution: 175268394 864379251 329514678 751836942 946752183 238941765 693425817 517683429 482197536_________________Cheers, Mike
mhparker
Grandmaster

Joined: 20 Jan 2007
Posts: 345
Location: Germany

Posted: Sun Oct 07, 2007 3:12 pm    Post subject:

 Andrew wrote: It still seems easier than A71. It's already got further than I've reached with A71 where I haven't yet managed anything in c3.

Step 14 made a big difference. The other key move was the partial conflicting combination in step 27. However, even without that, there would have been a second chance. It can namely be shown that 23(4)n89 cannot contain a 1, because it would require either {679} within n8 (blocked by r9c5) or {589} in n8 (blocked by 23(4)n78, which requires either 9 or both of {58}, at least one of which would have to be in n8). This means that 1 can be eliminated from r9c7, leaving a hidden single in c7 at r5c7 = 1.

Overall, I would rate the A71V2 at around 1.5. The V1 could be at least as difficult, but can't really say, because I interrupted it when the V2 arrived.
_________________
Cheers,
Mike
gary w

Joined: 07 Sep 2007
Posts: 84
Location: south wales

 Posted: Mon Oct 08, 2007 11:24 pm    Post subject: assassin 71 v2 Full wt looks very impressive.I did it like this;(since solution posted haven't used tiny text) 1.Prelims include a)r259c7=8 -> 1{25/34} b)r29c5 ={79} c)r18c5={68} 2. r2c5 <>1 -> r1c56r2c6={789} blocked by r2c5 3. But,can see "by inspection" that if r9c7=1 -> (r5c7=2,r2c7=5) then a)r9c5=7 (because the 9 must be in the 22/3 block at r8c56r9c6) b)r2c5=9 c)cannot complete the 25/4 cage N2/3. 4. So r5c7=1 r5c6=2 r67c6={15} r67c5=42 (unique rectangle...that again !!) Mop up now. Took me less than 1.5 hours. To me this seems more like spotting a conflicting combo rather than T&E..certainly no more difficult to see than some "conflicting combos" in earlier wts. So there Ruud..I reckon this one was much easier than V1 !!!
mhparker
Grandmaster

Joined: 20 Jan 2007
Posts: 345
Location: Germany

Posted: Tue Oct 09, 2007 11:25 am    Post subject: Re: assassin 71 v2

Hi folks,

 gary w wrote: r67c5=42 (unique rectangle...that again !!)

That's annoying - I should have seen that! Staring me right in the face in the second marks pic I posted! Ah well, at least Andrew will be pleased that I stuck to the more conventional route, avoiding the UR (albeit unintentionally)...

In the meantime, here's another one to get your teeth into.

Assassin 71 V1.5 (Est. rating: 1.25)

3x3::k:5376:5376:3586:3586:5124:5124:6406:6406:6406:4105:5376:5376:3586:3586:5124:5124:3344:6406:4105:4105:2836:2837:4886:1815:2328:3344:3344:4635:4105:2836:2837:4886:1815:2328:6178:3344:4635:4635:3622:3622:4886:3369:3369:6178:6178:5933:4635:2607:2096:2097:1842:2867:5428:6178:5933:5933:2607:2096:2097:1842:2867:5428:5428:5439:5933:5697:5697:4419:4419:5701:5701:5428:5439:5439:5439:5697:5697:4419:4419:5701:5701:

Have a nice day!
_________________
Cheers,
Mike
Andrew
Grandmaster

Joined: 11 Aug 2006
Posts: 300
Location: Lethbridge, Alberta

Posted: Tue Oct 09, 2007 5:53 pm    Post subject: Re: assassin 71 v2

 mhparker wrote: Ah well, at least Andrew will be pleased that I stuck to the more conventional route, avoiding the UR (albeit unintentionally)...

I've got no problem with others using UR if they want to.

I did happen to spot one today while solving the daily "plain vanilla" sudoku on www.sudoku.org.uk but didn't use it . That puzzle came out fairly quickly anyway.
Andrew
Grandmaster

Joined: 11 Aug 2006
Posts: 300
Location: Lethbridge, Alberta

Posted: Tue Oct 09, 2007 6:08 pm    Post subject:

 mhparker wrote: Overall, I would rate the A71V2 at around 1.5. The V1 could be at least as difficult, but can't really say, because I interrupted it when the V2 arrived.

I've almost finished A71 after several days. Just in the final tidying up stages. About to go back and insert another naked pair after realising that I hadn't been thorough enough with my clean-up!

A71 must be one of the hardest ever V1s! Definitely at least one rating level about A71V2 so I'll go along with Afmob's rating of 1.75. I think this is the first time that a V1 has been harder than the V2.

Whether it's actually the hardest ever I don't know. There were several very difficult ones about a year ago; A24, A26, A31, A33 and A34. Three of them are still in my Unfinished folder and one of those was done on the forum as a "tag" solution. Must try to find time to have another go at those three and see if I can now manage to finish them using what I've learned in the last year.

I mention those earlier Assassins because newer members of the forum may not have come across them. They can make a change from doing variants, particularly those variants which have the same cage pattern but different cage totals. Variants where subtle changes have been made to the cage pattern are a different matter; they are more like new puzzles.
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