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 Post subject: Assassin 286
PostPosted: Thu Mar 06, 2014 10:00 pm 
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Grand Master
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Joined: Wed Apr 16, 2008 1:16 am
Posts: 1044
Location: Sydney, Australia
I found this to be an old-school Assassin: took me a long time to find the key area in order to make a reasonable solution. Also found an OTT (over the top) move which would have been great for a v1.5 but couldn't close up the front door...anyway, hope you find it enough of a challenge as is. SudokuSolver score, 1.20

Assassin 286

Image
code: paste into solver:
3x3::k:2304:2304:5377:5377:11522:11522:11522:11522:11522:2304:2819:2819:5377:11522:4356:4356:11522:11522:6405:6405:6405:6405:6405:7430:4356:4356:11522:6405:3591:5896:5896:7430:7430:7430:1289:1289:2570:3591:1803:5896:5896:7430:7436:3853:3854:2570:3087:1803:4624:2321:2321:7436:3853:3854:11538:3087:3087:4624:7436:7436:7436:2579:2579:11538:11538:4624:4624:11538:2324:3349:3349:2579:11538:11538:11538:11538:11538:2324:2324:3606:3606:
solution:
+-------+-------+-------+
| 3 2 9 | 5 6 8 | 4 7 1 |
| 4 5 6 | 7 2 1 | 8 3 9 |
| 7 1 8 | 3 4 9 | 6 2 5 |
+-------+-------+-------+
| 2 6 5 | 9 8 7 | 3 1 4 |
| 1 8 4 | 6 3 2 | 5 9 7 |
| 9 7 3 | 1 5 4 | 2 6 8 |
+-------+-------+-------+
| 8 4 1 | 2 9 6 | 7 5 3 |
| 6 3 7 | 8 1 5 | 9 4 2 |
| 5 9 2 | 4 7 3 | 1 8 6 |
+-------+-------+-------+
Cheers
Ed


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PostPosted: Fri Mar 07, 2014 8:10 pm 
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Grand Master
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Joined: Mon Apr 21, 2008 9:44 am
Posts: 310
Location: MV, Germany
Thanks for the new Killer, Ed! Also this was one of the rare occassions where the most difficult move (step 4c and 4d) was not the most important one (step 4a).

A286 Walkthrough:
1. C789
a) 13(2) + 14(2) = 27(4) = 69{48/57} -> 6,9 locked for N9
b) 5 locked in R456C7 @ N6 for C7
c) Innies N9 = 8(2) = {17} -> R9C7 = 1, R7C7 = 7
d) Innies N6 = 10(3) = {235} locked for C7+N6
e) 5(2) @ N6 = {14} locked for R4
f) 13(2) = {49} locked for R8+N9 since (58) is a Killer pair of 14(2)
g) 14(2) = {68} locked for R9

2. R123
a) Innies+Outies R123: -7 = R4C1 - R3C6 -> R4C1 = 2, R3C6 = 9
b) 9 locked in 45(9) for N3
c) 17(4) = {1268/2348/2456} <> 7 since R23C7 = (468); R2C6+R3C8 = (1235)
d) 7 locked in 45(9) @ N3 for 45(9)
e) 25(6) = 12{3478/3568/4567} -> 1 locked for R3
f) 1 locked in 45(9) @ N3 for 45(9)

3. R456
a) 2 locked in 29(5) @ N6 = 279{38/56} -> R7C5 = 9; R7C6 = (68)
b) 7(2) <> 5
c) 7(2) + 10(2) = 17(4) = 13{49/67} -> 1,3 locked for N4
d) Innies N4 = 12(2) = {57}/[84]
e) 12(3) <> 8 since R6C2 = (457)
f) 7 locked in R456C6 @ C6 for N5

4. C456+N7 !
a) ! 7 locked in Outies C1234 @ C5 = 15(4) = 17{25/34} -> 1 locked for C5
b) 45(9) must have 6 -> 6 locked for N7
c) 12(3) = 4{17/35} since 7{23} blocked by R7C89 = (235)
d) ! 12(3): R6C2 <> 4 since 4{35} blocked by R7C89 = (235)

5. R456
a) Innies N4 = 12(2) = {57} locked for N4
b) 14(2) = {68} locked for C2+N4
c) 10(2) = {19} locked for C1+N4
d) 7(2) = {34} locked for C3
e) 12(3) = {147} since R6C2+R7C4 = (157) -> R6C2 = 7, R7C3 = 1, R7C2 = 4
f) R4C3 = 5, R4C7 = 3
g) 29(5) @ N6 = {25679} -> R7C6 = 6
h) Innie N5 = R6C4 = 1

6. R123+N56
a) Hidden Single: R2C6 = 1 @ C6, R3C2 = 1 @ R3
b) 9(3) = {234} -> R1C2 = 2; 3,4 locked for C1+N1
c) 11(2) = [56] -> R2C2 = 5, R2C3 = 6
d) Hidden Single: R4C4 = 9 @ R4
e) 23(4) = {3569} -> R5C5 = 3, R5C4 = 6
f) 25(6) = {123478} since R3C13 = (78) -> R3C5 = 4, R3C4 = 3; 7,8 locked for R3+N1
g) 17(4) = {1268} -> R2C7 = 8, R3C7 = 6, R3C8 = 2
h) R1C3 = 9, R1C7 = 4, R8C7 = 9, R8C8 = 4, R4C8 = 1, R1C1 = 3, R2C4 = 7 -> R1C4 = 5, R1C8 = 7
i) 15(2) @ C8 = [96] -> R5C8 = 9, R6C8 = 6

7. Rest is singles.

Rating:
1.0. I used an ALS combo blocker.


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 Post subject: Re: Assassin 286
PostPosted: Sat Mar 08, 2014 3:08 am 
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Grand Master
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Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1895
Location: Lethbridge, Alberta, Canada
Thanks Ed for your latest killer. It starts easily, then I had to search harder for steps although they weren't difficult ones.

Here is my walkthrough for Assassin 286:
Step 22 simplified. Thanks Afmob

Prelims

a) R2C23 = {29/38/47/56}, no 1
b) R45C2 = {59/68}
c) R4C89 = {14/23}
d) R56C1 = {19/28/37/46}, no 5
e) R56C3 = {16/25/34}, no 7,8,9
f) R56C8 = {69/78}
g) R56C9 = {69/78}
h) R6C56 = {18/27/36/45}, no 9
i) R8C78 = {49/58/67}, no 1,2,3
j) R9C89 = {59/68}
k) 9(3) cage at R1C1 = {126/135/234}, no 7,8,9
l) 21(3) cage at R1C3 = {489/579/678}, no 1,2,3
m) 10(3) cage at R7C8 = {127/136/145/235}, no 8,9
n) 9(3) cage at R8C6 = {126/135/234}, no 7,8,9
o) And, of course, both 45(9) cages = {123456789}

1. R8C78 = {49/67} (cannot be {58} which clashes with R9C89), no 5,8
1a. Killer pair 6,9 in R8C78 and R9C89, locked for N9

2. Naked quad {6789} in R56C89, locked for N6
2a. 5 in N6 only in R456C7, locked for C7

3. 45 rule on N9 2 innies R79C7 = 8 = [71], clean-up: no 6 in R8C78
3a. Naked pair {49} in R8C78, locked for R8 and N9, clean-up: no 5 in R9C89
3b. Naked pair {68} in R9C89, locked for R9
3c. R9C7 = 1 -> R89C6 = 8 = [35/53/62]

4. 1 in N6 only in R4C89 = {14}, locked for R4 and N6
4a. Naked triple {235} in R456C7, 2,3 locked for C7

5. 6,8 in C7 only in R123C7, locked for N3
5a. Min R23C7 = {46} = 10 -> max R2C6 + R3C8 = 7, no 6,7,8,9 in R2C6 + R3C8 (17(4) cage cannot be 6{46}1)
5b. 6,8 in 45(9) cage at R1C5 only in R1C567 + R2C5, CPE no 6,8 in R1C4
5c. 7 in N3 only in R12C8 + R123C9, locked for 45(9) cage at R1C5, no 7 in R1C56 + R2C5

6. 4,7,9 in R9 only in R9C12345, locked for 45(9) cage at R7C1, no 4,9 in R7C1, no 7 in R8C125
6a. 7 in R8 only in R8C45, locked for 18(4) cage at R6C4, no 7 in R6C4
6b. 18(4) cage cannot contain both of 7,9 -> no 9 in R67C4

7. 45 rule on R123 1 innie R3C6 = 1 outie R4C1 + 7 -> R3C6 = 9, R4C1 = 2, clean-up: no 8 in R56C1, no 5 in R56C3
7a. Max R12C4 = 15 -> min R1C3 = 6
7b. 45(9) cage at R1C5 = {123456789}, 9 locked for N3

8. 2 in C7 only in R56C7 -> 29(5) cage at R5C7 contains 2,7 = {23789/25679} -> R7C5 = 9, R7C6 = {68}
8a. 1 in R7 only in R7C1234, CPE no 1 in R8C3

9. R56C1 = {19/37} (cannot be {46} which clashes with R56C3), no 4,6
9a. Killer pair 1,3 in R56C1 and R56C3, locked for N4

10. 45 rule on N4 2 remaining innies R4C3 + R6C2 = 12 = [57/75/84]
10a. CPE 4 in N4 only in R56C3 + R6C2, CPE no 4 in R7C3

11. 2 in R3 only in R3C89, locked for N3
11a. 45 rule on R12 3 outies R3C789 = 13 contains 2 = {238/247/256}, no 1 in R3C89
11b. R3C7 = {468} -> no 4 in R3C89
11c. 1 in N3 only in R12C89, locked for 45(9) cage at R1C5, no 1 in R1C56 + R2C5

12. 45 rule on N1 1 innie R1C3 = 2 remaining outies R3C45 + 2
12a. Max R3C45 = 7, no 7,8 in R3C45

13. 7 in N2 only in R12C4, locked for C4 and 21(3) cage at R1C3, no 7 in R1C3
13a. 21(3) cage at R1C3 contains 7 = {579/678}, no 4

14. R8C3 = 7 (hidden single in R8), clean-up: no 4 in R2C2, no 5 in R6C2 (step 10)
14a. R9C5 = 7 (hidden single in R9), R4C6 = 7 (hidden single in R4), clean-up: no 2 in R6C56
14b. 4 in N8 only in R79C4, locked for C4

15. 12(3) cage at R6C2 = {147/246} (cannot be {138/156} because R6C2 only contains 4,7, cannot be {237/345} which clash with 10(3) cage at R7C8, ALS block), no 3,5,8 in R7C23, 4 locked for C2
15a. 1 of {147} must be in R7C3 -> no 1 in R7C2
15b. 3,5,8 in N7 only in 45(9) cage at R7C1, no 3,5,8 in R8C5 + R9C4

16. R8C3 = 7 -> 18(4) cage at R6C4 = {1278/1467/2367} (cannot be {2457} which clashes with R9C4), no 5

17. 5 in N8 only in R89C6 (step 3c) = {35}, locked for C6 and N8, clean-up: no 4,6 in R6C5

18. 17(4) cage at R2C6 cannot contain all of 4,6,8, R23C7 = {468} -> no 4 in R2C6
[I’ve noted that 2 in N23 is only in 45(9) cage at R1C5 and 17(4) cage -> 17(4) cage must contain 2. Maybe I’ll use that later.]

19. 29(5) cage at R3C6 contains 7,9 = {23789/25679/34679} (cannot be {14789} because 1,4 only in R5C6), no 1
19a. 2,4 only in R5C6 -> R5C6 = {24}
19b. 5 of {25679} must be in R4C7 -> no 5 in R4C5

20. 9(3) cage at R1C1 = {126/135/234}
20a. 2 of {126} must be in R1C2 -> no 6 in R1C2
20b. 5 of {135} must be in R12C1 (R12C1 cannot be {13} which clashes with R56C1), no 5 in R1C2

21. 12(3) cage at R6C2 (step 15) = {147/246} -> R7C23 = {14/26}
21a. Law of Leftovers (LoL) for N7, because of 45(9) cage at R7C1, 2 remaining outies R8C5 + R9C4 must exactly equal 2 remaining innies R7C23, R7C23 = {14/26} -> R8C5 + R9C4 = {14/26} = [14/62]
21b. 2 in N8 only in R789C4, locked for C4
21c. R6C7 = 2 (hidden single in R6)

22. 9 in N5 only in 23(4) cage at R4C3 = {1589/2489/3569}
22a. 45 rule on R4 3 remaining innies R4C234 = 1 outie R5C6 + 18
22b. R5C6 = {24} -> R4C234 = 20,22 = {569/589} (cannot be {389} because 23(4) cannot contain both of 3,8), 5 locked for R4 -> R4C7 = 3

23. R5C7 = 5, R9C6 = 6 (cage sum), R8C5 = 1, R9C4 = 4 (step 21a), clean-up: no 3 in R6C5, no 8 in R6C6
23a. R78C4 = {28}, locked for C4, R8C3 = 7 -> R6C4 = 1 (cage sum), R6C6 = 4 -> R6C5 = 5
23b. R5C6 = 2 -> R4C5 = 8 (cage sum)
[Routine clean-ups omitted from here.]

24. R4C3 = 5, R45C2 = {68} (only remaining combination) = [68], R6C3 = 3 -> R5C3 = 4

25. R6C2 = 7 -> R7C23 = 5 = [41]

26. R1C6 = 8
26a. 21(3) cage at R1C3 (step 13a) = {579} (only remaining combination) -> R1C3 = 9, R12C4 = {57}, 5 locked for C3
26b. 2 in N2 only in R12C5, locked for 45(9) cage at R1C5

27. R2C6 = 1, R3C8 = 2 (hidden single in R3) -> R23C7 = 14 = {68}, 6 locked for C3

28. R3C789 (step 11a) = {256} (only remaining combination, cannot be {238} which clashes with R3C34, ALS block) -> R3C79 = [65], R3C12345 = [71834]

29. 9(3) cage at R1C1 = {234} (only remaining combination) -> R1C2 = 2, R12C1 = {34}, 3 locked for C1 and N1

30. R4C4 = 9, R5C45 = [63], R56C1 = [19]

31. R1C7 = 4, R8C78 = [94], R4C89 = [14], R2C2 = 5, R2C4 = 7

32. Naked pair {23} in R78C9, locked for C9 and N9 -> R2C9 = 9, R5C9 = 7 -> R6C9 = 8

and the rest is naked singles.

Rating Comment:
I'll rate my walkthrough for A286 at Hard 1.0. I used ALS blocks, LoL and a block using cage interactions.


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 Post subject: Re: Assassin 286
PostPosted: Sun Mar 09, 2014 6:59 am 
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Grand Master
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Joined: Wed Apr 16, 2008 1:16 am
Posts: 1044
Location: Sydney, Australia
Great solution Afmob! I missed his key "45" (his step 4a) so found this puzzle to be much closer to Andrew's way though his is much, much better than my first solve. Here's an alternate way to finally crack the puzzle.

A286 alt crack from after Andrew's step 20b.
3 more steps:
candidates + with cage pattern:
.-------------------------------.-------------------------------.-------------------------------.
| 13456 123 689 | 57 234568 2468 | 4689 134579 134579 |
| 13456 2356789 2345689 | 5678 234568 12 | 468 134579 134579 |
| 1345678 135678 134568 | 1356 13456 9 | 468 235 2357 |
:-------------------------------+-------------------------------+-------------------------------:
| 2 5689 58 | 35689 368 7 | 35 14 14 |
| 1379 5689 1346 | 1235689 1234568 24 | 235 6789 6789 |
| 1379 47 1346 | 12368 1358 1468 | 235 6789 6789 |
:-------------------------------+-------------------------------+-------------------------------:
| 13568 246 126 | 12468 9 68 | 7 235 235 |
| 13568 123568 7 | 1268 126 35 | 49 49 235 |
| 3459 2359 23459 | 24 7 35 | 1 68 68 |
'-------------------------------.-------------------------------.-------------------------------'
.-----------------------------------------------------------------------.
|( 9) : |(21) : |(45) : : : : |
| 1 3 : 123 | : | 23 : 2 : : 1 3 : 1 3 |
| 456 : | 6 : 5 | 456 : 4 6 : 4 6 : 45 : 45 |
| : | 89 : 7 | 8 : 8 : 89 : 7 9 : 7 9 |
|.......--------|-------:.......|.......----------------:.......:.......|
| |(11) : | | |(17) : | : |
| 1 3 | 23 : 23 | | 23 | 12 : | 1 3 : 1 3 |
| 456 | 56 : 456 | 56 | 456 | : 4 6 | 45 : 45 |
| | 789 : 89 | 78 | 8 | : 8 | 7 9 : 7 9 |
|-------|---------------|-------|-------|-------:.......|-------:.......|
|(25) : : : : |(29) | : | |
| 1 3 : 1 3 : 1 3 : 1 3 : 1 3 | | : 23 | 23 |
| 456 : 56 : 456 : 56 : 456 | 9 | 4 6 : 5 | 5 |
| 78 : 78 : 8 : : | | 8 : | 7 |
|.......--------------------------------|.......|---------------|-------|
| |(14) |(23) : | : : |( 5) : |
| | | : 3 | 3 : : 3 | 1 : 1 |
| 2 | 56 | 5 : 56 | 6 : 7 : 5 | 4 : 4 |
| | 89 | 8 : 89 | 8 : : | : |
|-------|.......|-------:.......|-------:.......--------|---------------|
|(10) | |( 7) | : | |(29) |(15) |(15) |
| 1 3 | | 1 3 | 123 : 123 | 2 | 23 | | |
| | 56 | 4 6 | 56 : 456 | 4 | 5 | 6 | 6 |
| 7 9 | 89 | | 89 : 8 | | | 789 | 789 |
|.......|-------|.......|---------------|-------|.......|.......|.......|
| |(12) | |(18) |( 9) : | | | |
| 1 3 | | 1 3 | 123 | 1 3 : 1 | 23 | | |
| | 4 | 4 6 | 6 | 5 : 4 6 | 5 | 6 | 6 |
| 7 9 | 7 | | 8 | 8 : 8 | | 789 | 789 |
|-------|.......|-------|.......|---------------|.......|-------|-------|
|(45) | : | | : : |(10) : |
| 1 3 | 2 : 12 | 12 | : : | 23 : 23 |
| 56 | 4 6 : 6 | 4 6 | 9 : 6 : 7 | 5 : 5 |
| 8 | : | 8 | : 8 : | : |
|.......|---------------|.......|-----------------------|-------:.......|
| : | : | |( 9) |(13) : | |
| 1 3 : 123 | : 12 | 12 | 3 | : | 23 |
| 56 : 56 | 7 : 6 | 6 | 5 | 4 : 4 | 5 |
| 8 : 8 | : 8 | | | 9 : 9 | |
|.......:.......|---------------|.......|.......|---------------|-------|
| : : : : | : |(14) : |
| 3 : 23 : 23 : 2 : | 3 : | : |
| 45 : 5 : 45 : 4 : 7 | 5 : 1 | 6 : 6 |
| 9 : 9 : 9 : : | : | 8 : 8 |
.-----------------------------------------------------------------------.
21. "45" on n5: 2 remaining outies r4c37 - 7 = 1 innie r6c4
21a. = [531/856]
21b. r6c4 = (16)

22. 23(4)r4c3 must have 9 for n5 and one of 5,8 for r4c3 = {1589/2489/3569}
22a. but {2489} blocked by r5c6 = (24)
22b. 23(4)r4c3 = {1589/3569}(no 2,4)

23. Hidden singles 2 and 4 in n5 -> r5c6 = 2, r6c6 = 4, r6c5 = 5, r6c2 = 7, r4c3 = 5 (h12(2)r4c3+r6c2)
etc
Cheers
Ed


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