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 Post subject: Assassin 414
PostPosted: Fri Apr 01, 2022 8:28 am 
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Grand Master
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Joined: Wed Apr 16, 2008 1:16 am
Posts: 1043
Location: Sydney, Australia
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Quite enjoyed this puzzle even though it was hard getting started. Further in found some interesting steps so was very glad I persisted. SS gives it 1.75. JSudoku uses just two advanced steps which suggests an easier one.

Andrew has been doing some great work getting all the pics in the archives to work. Realised I used to make some very pretty pics so have tried a bit harder with this one.

triple click code:
3x3::k:4608:4608:4608:4353:2818:2818:3587:3587:9732:2309:4608:5382:4353:4353:9732:9732:9732:9732:2309:2311:5382:5382:5382:9732:7432:7432:9732:3849:2311:7690:7690:6411:9732:7432:3084:3084:3849:3853:7690:6411:6411:6411:7432:3084:4110:3853:3853:7690:2063:6411:7432:7432:2064:4110:3857:7690:7690:2063:3858:3858:3858:2064:2323:3857:3857:2580:2580:4117:4117:3858:5910:2323:3857:2327:2327:3352:3352:4117:5910:5910:5910:
solution:
+-------+-------+-------+
| 2 1 7 | 6 8 3 | 9 5 4 |
| 5 8 9 | 4 7 2 | 6 3 1 |
| 4 3 6 | 1 5 9 | 7 2 8 |
+-------+-------+-------+
| 7 6 1 | 8 9 5 | 3 4 2 |
| 8 4 3 | 7 2 1 | 5 6 9 |
| 9 2 5 | 3 6 4 | 8 1 7 |
+-------+-------+-------+
| 6 9 4 | 5 1 8 | 2 7 3 |
| 1 5 8 | 2 3 7 | 4 9 6 |
| 3 7 2 | 9 4 6 | 1 8 5 |
+-------+-------+-------+
Cheers
Ed


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 Post subject: Re: Assassin 414
PostPosted: Wed Apr 06, 2022 1:07 am 
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Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1894
Location: Lethbridge, Alberta, Canada
Thanks Ed for your latest Assassin and for your nice comments about my work on the archives; there's also a Texas Jigsaw Killer archive in Other Variants for those who are interested in jigsaw killers, most of them somewhat easier than Assassins.

Yes, this puzzle was hard getting started before I was able to make real progress. Unusually my solving path didn't contain any forcing chains.

Thanks Ed for pointing out an error in my original step 8b; a short rework from there before continuing with my original steps.

Here's my walkthrough for Assassin 414:
Prelims

a) R1C56 = {29/38/47/56}
b) R1C78 = {59/68}
c) R23C1 = {18/27/36/45}, no 9
d) R34C2 = {18/27/36/45}, no 9
e) R45C1 = {69/78}
f) R56C9 = {79}
g) R67C4 = {17/26/35}, no 4,8,9
h) R67C8 = {17/26/35}, no 4,8,9
i) R78C9 = {18/27/36/45}, no 9
j) R8C34 = {19/28/37/46}, no 5
k) R9C23 = {18/27/36/45}, no 9
l) R9C45 = {49/58/67}, no 1,2,3
m) 38(8) cage at R1C9 = {12345689}, no 7

1a. Naked pair {79} in R56C9, locked for C9 and N6, clean-up: no 1 in R7C8, no 2 in R78C9
1b. R1C56 = {29/38/47} (cannot be {56} which clashes with R1C78), no 5,6
1c. 7 in N3 only in R3C78, locked for R3 and 29(6) cage at R3C7, clean-up: no 2 in R2C1, no 2 in R4C2

2a. 45 rule on N7 3 innies R7C23 + R8C3 = 21 = {489/579/678}, no 1,2,3, clean-up: no 7,8,9 in R8C4
2b. 45 rule on N9 2 outies R7C56 = 1 innie R7C8 + 2, IOU no 2 in R7C56
2c. Max R7C8 = 7 -> max R7C56 = 9, no 9 in R7C56
2d. 15(4) cage at R7C5 = {1248/1257/1347/1356/2346} (cannot be {1239} = {13}{29} which clashes with R7C8 = 2, step 2b), no 9
2e. 9 in R7 only in R7C123, locked for N7, clean-up: no 1 in R8C4
2f. 45 rule on N9 3 innies R7C78 + R8C7 = 13 = {157/238/247/256/346} (cannot be {148} because no 1,4,8 in R7C8)
2g. 45 rule on R9 2 innies R9C16 = 1 outie R8C8
2h. Min R9C16 = 3 -> min R8C8 = 3
2i. Max R8C8 = 9 -> max R9C16 = 9, no 9 in R9C6
2j. 45 rule on N89 3 innies R78C4 + R7C8 = 14
2k. R78C4 cannot total 12 -> no 2 in R7C8, clean-up: no 6 in R6C8
2l. R78C4 cannot total 8 (which clashes with R67C4, CCC) -> no 6 in R7C8, clean-up: no 2 in R6C8
2m. R7C8 = {357} -> R7C56 = 5,7,9 must contain one even number -> 15(4) cage = {1248/1347/1356/2346} (cannot be {1257} because 2 only in R78C7)
2n. 45 rule on N47 2 outies R48C4 = 1 innie R4C2 + 4, IOU no 4 in R8C4, clean-up: no 6 in R8C3

3a. 45 rule on N1 2 outies R3C45 = 1 innie R3C2 + 3, IOU no 3 in R3C45
3b. 45 rule on N2 4 innies R2C6 + R3C456 = 17 = {1259/1268/1358/2456} (cannot be {1349/2348} which clash with R1C56)
3c. 17(3) cage at R1C4 = {179/269/359/368/458/467} (cannot be {278} which clashes with R1C56)
3d. 45 rule on R89 2 outies R7C19 = 1 innie R8C7 + 5, IOU no 5 in R7C1

4a. 12(3) cage at R4C8 = {138/156/246/345}
4b. R45C8 cannot be {13} which clashes with R67C8 -> no 8 in R4C9

[Odds and evens in N8]
5a. R7C8 is odd -> R7C56 must be odd (step 2b)
5b. R7C8 is odd -> R78C4 must be odd (step 2j)
5c. R7C56, R78C4 and R9C45 are all odd so must each contain one even number -> 16(3) cage at R8C5 must contain only one even number = {169/178/259/349/358/367} (cannot be {268} with three even numbers, cannot be {457} which clashes with R9C45)
[Unfortunately not particularly useful (and unnecessary after step 6c) unlike wellbeback’s powerful odds and evens step in Assassin 413.]

6a. 45 rule on N89 2 innies R7C48 = 1 outie R8C3 + 4
6b. R8C3 = {478} -> R7C48 = 8,11,12 = [17]/{35/57} (cannot be {26} because no 2,6 in R7C8, cannot be [65] because R7C48 + R8C3 = [657] clashes with R7C23 + R8C3, step 2a), no 2,6 in R7C4, clean-up: no 2,6 in R6C4
6c. R7C48 = [17]/{35/57} = 8,12 -> no 7 in R8C3, clean-up: no 3 in R8C4
6d. R7C48 + R8C3 (step 2a) = {489/678} (cannot be {579} because R8C3 only contains 4,8), no 5
6e. R7C48 + R8C3 = {489} (cannot be {678} = {67}8 which clashes with R7C48 + R8C3 = {57}8), locked for N7, 9 locked for 30(6) cage at R4C4, clean-up: no 1,5 in R9C23
6f. R7C48 + R8C3 = {489}, CPE no 4,8 in R456C3
6g. R9C45 = {49/58} (cannot be {67} which clashes with R9C23), no 6,7

7a. 16(3) cage at R8C5 (step 5c) = {169/178/349/358/367} (cannot be {259} which clashes with R9C45), no 2
7b. R8C4 = 2 (hidden single in N8) -> R8C3 = 8, clean-up: no 1 in R7C9
7c. Naked pair {49} in R7C23, 4 locked for R7 and 30(6) cage at R4C4, clean-up: no 5 in R8C9
7d. 45 rule on N47 1 remaining outie R4C4 = 1 innie R4C2 + 2, no 7,8 in R4C2, no 1 in R4C4, clean-up: no 1,2 in R3C2
7e. R8C3 = 8 -> R7C48 = 12 (step 6a) = {57}, locked for R7, clean-up: no 5,7 in R6C4, no 5 in R6C8, no 4 in R8C9
7f. Naked pair {13} in R6C48, locked for R6
7g. 15(4) cage at R7C5 (step 2m) = {1248/1356/2346} (cannot be {1347} because 4,7 only in R8C7), no 7
7h. 4,5 of 15(4) cage only in R8C7 -> R8C7 = {45}
7i. 2 of {1248} must be in R7C7 -> no 8 in R7C7
7j. R7C78 + R8C7 (step 2f) = {157/247} (cannot be {256/346} because no 2,3,6 in R7C8 + R8C7) -> R7C8 = 7, R78C7 = [15/24], R6C8 = 1, R67C4 = [35], clean-up: no 1,3 in R4C2 (step 7d), no 6,8 in R3C2, no 8 in R9C45
7k. Naked pair {49} in R9C45, locked for R9 and N8
7l. R8C78 = [49] (hidden pair in N9) -> R7C7 = 2, clean-up: no 5 in R1C7
7m. 2,4 in N6 only in 12(3) cage at R4C8 = {246}, 6 locked for N6
7n. Naked triple {358} in R456C7, locked for C7 and 29(6) cage at R3C8, clean-up: no 6 in R1C8
7o. R1C7 = 7 (hidden single in N3), R456C7 = {358} = 16 -> R3C8 + R6C6 = 6 = {24}
7p. Naked pair {24} in R3C8 + R6C6, CPE no 2,4 in R3C6
7q. Caged X-Wing for 2,4 in R3C8 + R6C6 and 38(8) cage at R1C9 in C6 and N3 -> 2,4 in R246C6, locked for C6, clean-up: no 7,9 in R1C5
7r. Naked triple {246} in R345C8, locked for C8, 6 locked for N6
7s. 5 in N9 only in R9C89, locked for R9
7t. 45 rule on N1 3 innies R2C3 + R3C23 = 18 = {369/459/567} (cannot be {189/279} because R3C2 only contains 3,4,5), no 1,2
7u. 3,4 of {369/459} must be in R3C2 (R23C3 cannot be {49} which clashes with R7C3 -> no 3,4 in R23C3
7v. R3C45 = R3C2 + 3 (step 3a)
7w. Max R3C2 = 5 -> max R3C45 = 8, no 8,9 in R3C45
7x. R3C2 = {345} -> R3C45 = 6,7,8 = [15]/{16}/[62] (cannot be {24} which clashes with R3C8, cannot be {25} because 2,5 only in R3C5), no 4

8a. R4C4 = R4C2 + 2 (step 7d) -> R4C24 = [46/57/68]
8b. R7C23 = {49} = 13 -> R456C3 + R4C4 = 17 = {1358/1367} (cannot be {1268/2357} which clash with R4C24, CCC) -> R456C3 = {135/136/137}, no 2
[Reworked from here; I’d overlooked that {1367} can be either {136}7 or {137}6]
8c. R6C3 = {567} -> R45C3 = {13}, locked for C3 and N4, clean-up: no 6 in R9C2
8d. 2 in N4 only in 15(3) cage at R5C2 = {249/258} (cannot be {267} which clashes with R45C1), no 6,7
8e. 45 rule on N5 3 remaining innies R4C46 +R6C6 = 17 = [764/782/854] (cannot be [692] because R4C4 + R4C89 = {246} clashes with R4C24, CCC)
8f. R4C4 = {78} -> R4C2 = {56}, R3C2 = {34}, R6C3 = {56}
[Then continuing as previously, with sub-steps renumbered]

8g. Naked pair {56} in R4C2 + R6C3, locked for N4, clean-up: no 9 in R45C1
8h. Naked pair {78} in R45C1, locked for C1, 8 locked for N4, clean-up: no 1,2 in R23C1
8i. Naked triple {249} in R567C2, locked for C2, 2 locked for N4
8j. R3C2 = 3 -> R4C2 = 6, R4C4 = 8, R45C1 = [78], R6C3 = 5, R9C2 = 7 -> R9C3 = 2, clean-up: no 6 in R23C1
8k. Naked pair {45} in R23C1, locked for C1 and N1 -> R6C1 = 9, R56C9 = [97]
8l. 45 rule on N1 2 remaining innies R23C3 = 15 = {69}, locked for N1, 9 locked for C3
8m. R23C3 = 15 -> R3C45 = 6 = [15], R23C1= [54], R3C8 = 2, R6C6 = 4
8n. R1C3 = 7, clean-up: no 4 in R1C5

9a. 45 rule on N5 1 remaining innie R4C6 = 5
9b. R1C8 = 5 (hidden single in N3) -> R1C7 = 9, clean-up: no 2 in R1C5
9c. 38(8) cage at R1C9 = {12345689} -> R23C6 = [29]
9d. R3C39 = [68], clean-up: no 1 in R8C9
9e. Naked pair {36} in R78C9, locked for C9 and N9
9f. R78C7 = [24] -> R7C56 = 9 = {18} (cannot be {36} which clashes with R7C9), locked for N8, 1 locked for R7


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 Post subject: Re: Assassin 414
PostPosted: Mon Apr 11, 2022 7:24 am 
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Joined: Wed Apr 16, 2008 1:16 am
Posts: 1043
Location: Sydney, Australia
I started in the same areas as Andrew but a different middle. Really enjoyed his step 5. [Thanks to Andrew for checking my WT. So many typos!!]
WT for a414:
Preliminaries from SudokuSolver
Cage 16(2) n6 - cells ={79}
Cage 14(2) n3 - cells only uses 5689
Cage 15(2) n4 - cells only uses 6789
Cage 8(2) n58 - cells do not use 489
Cage 8(2) n69 - cells do not use 489
Cage 13(2) n8 - cells do not use 123
Cage 9(2) n1 - cells do not use 9
Cage 9(2) n7 - cells do not use 9
Cage 9(2) n14 - cells do not use 9
Cage 9(2) n9 - cells do not use 9
Cage 10(2) n78 - cells do not use 5
Cage 11(2) n2 - cells do not use 1
Cage 38(8) n235 - cells ={12345689}

This is a highly optimised solution so any clean-up is stated.

1. 16(2)n6 = {79}: both locked for c9 and n6
1a. no 1 in r7c8

2. "45" on n89: 1 outie r6c4 + 6 = 2 innies r7c8 + r8c4
2a. r6c4 and r8c4 see each other so their difference can't be 0 -> no 6 in r7c8 (IOU)

3. "45" on n9: 1 innie r7c8 + 2 = 2 outies r7c56
3a. -> no 2 in r7c56 (IOU)
3b. max. r7c8 = 7 -> max. r7c56 = 9 -> no 9 in r7c56

4. "45" on n7: 3 innies r7c23 + r8c3 = 21 = {489/579/678}(no 1,2,3)
4a. no 7,8,9 in r8c4

5. "45" on n89: 3 innies r7c48 + r8c4 = 14
5a. r7c8 from (2357) and r8c4 from (12346) -> those two can't make 12 -> no 2 in r7c4
5a. r7c4 from (13567) -> r78c4 can't make 12 -> no 2 in r7c8

6. if 2 in n8 in 16(3) -> = {259} -> 13(2)n8 = {67}
or 16(3) is {268)
6a. ie, 2 must also have 6 in combined cage 29(5)
6b. or 2 in r8 in r8c4
6c. -> no 6 in r8c4 (Locking out cages)
6d. -> no 4 in r8c3

7. max. r8c4 = 4 -> min. r7c48 = 10 (innies n89=14)-> no 1 in r7c4

8. h21(3)n7 = {489/579/678} = 6 or 9 but not both
8a. "45" on r789: 4 innies r7c2348 = 25
8b. but {3589} as {89}{35} blocked since min. r7c48 = 10 (step 7)
8c. and {3679} blocked since r7c23 can't be both {69} and {36} in r7c48 is less than 10
8d. = {4579/4678} (no 3)
8e. must have 4 which is only in r7c23 -> h21(3)n7 = {489} only: all locked for n7, no 4,8,9, in r456c3 (Common Peer Elimination CPE), no 4 in r4c4
8f. 4 and 7 locked for r7
8g. r8c4 = (12)
8h. 7 only in one of 8(2)r6c48 -> 1 locked in r6c48 for r6

9. "45" on n9: 3 innies r7c8 + r78c7 = 13
9a. min. r7c8 = 5 -> max. r78c6 = 8 (no 8,9)

10. 9 in r7 only in n7: locked for n7
10a. -> r8c3 = 8 -> r8c4 = 2
10b. -> r7c48 = 12 (innies n89=14) = {57} only: 5 locked for r7
10c. -> 3 locked in r6c48 for r6 (ie, r6c48 = {13}
10d. and r7c23 = {49}: 9 locked for 30(6)

11. h13(3)n9 must have 5 or 7 for r7c8 = {157/247/256}(no 3) = 6 or 7

12. "45" on n9: 2 outies r7c56 = 1 innie r7c8 + 2
12a. but {16}[5] leaves no 6 or 7 for h13(3)n9
12b. = {18/36}[7]
12c. -> r6c8 = 1
12d. r67c4 = [35]
12e. and r78c7 = 6 (h13(3)n9) = [15/24]

13. r3c7 = 7 (hsingle n3)

14. "45" on n6: 2 remaining outies r3c8 + r6c6 = 6 = {24} only: both locked for 29(6) cage
14a. -> r456c7 = 16 (cages sum) = {358} only: all locked for c7 and n6
14b. -> r8c7 = 4
14c. -> r7c7 = 2 (1 remaining innie n9)

Loved finding this. It was available right at the beginning but is more powerful now.
15. no 7 in r234c6 -> r234c6 repeat in n3 in r1c78 + r3c8
15a. r3c6 sees r3c8 -> must repeat in the 14(2)n3 -> must be part of a h14(2) with one of r24c6
15b. "45" on n12: 3 innies r23c6 + r3c2 = 14
15c. -> r23c6 cannot sum to 14
15d. -> r34c6 = h14(2) = {59/68}
15e. -> r2c6 = r3c8 = (24)

16. naked pair {24} in r26c6: both locked for c6

17. 4 in r9 only in 13(2)n8 = {49} only: 9 locked for r9 and n8

18. "45" in n47: 1 innie r4c4 + 2 = 1 remaining outie r4c4
18a. but [46] blocked by r4c89 = {246} (Almost locked set ALS)
18b. = [57/68]
18c. r3c2 = (34)

19. "45" on n4: 4 innies r4c2 + r456c3 = 15
19a. but [5]{127} blocked by 7 also in r4c4 (step 18b)
19b. = {1356} only: all locked for n4; 1,3 also locked for c3
19b. -> r45c3 = {13} (hpair n4)

20. 15(2)n4 = {78}: both locked for c1 and n4

21. naked pair {78} in r4c14: 8 locked for r4

22. "45" on n5: 3 remaining innies r4c4 + r46c6 = 17
22a. must have one of 7,8 and one of 2,4 = {458/467}
22b. -> r6c6 = 4
22c. r4c6 = (56)

23. naked pair {56} in r4c26: both locked for r4

24. "45" on n1: 3 innies r2c3 + r3c23 = 18 and must have 3 or 4 for r3c2
24a. = {369/459}(no 2,7)
24b. 9 locked for n1, c3 and 21(4)

25. killer pair 5,6 in r23c3 + r6c3: both locked for c3

26. 9(2)n7 = {27}: both locked for r9

27. {56} blocked from 11(2)n2 by 14(2) needing one of them
27a. -> no 5,6 in 11(2)

Much easier now.
Cheers
Ed


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 Post subject: Re: Assassin 414
PostPosted: Thu Apr 14, 2022 8:36 pm 
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Posts: 282
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Spent ages looking at the wrong area of this. Finally found a more productive place. Will now see how the other WTs did it. Thanks Ed!
Assassin 414:
1. Innies n7 = r7c23 + r8c3 = +21(3)
-> Min r6c3 = 4, Max r8c4 = 6
IOD n47 -> r4c2 + 4 = r4c4 + r8c4
-> r8c4 cannot be 4
-> r8c3 from {4789}, r8c4 from (6321)

2. 16(2)n6 = {79} -> 8(2)r6c8 not [71]
Innies n89 = r78c4 + r7c8 = +14(3)
8(2)r6c4 -> r78c4 not +8 -> r7c8 not 6
Since r7c4 is max 7 and r8c4 from (1236) -> r78c4 not +12
-> r7c8 not 2
-> 8(2)r6c8 from [17] or {35}

3. Innies n9 = r7c78 + r8c7 = +13(3)
8(2)r6c8 cannot be [53] since that puts 15(4)r7c5 = [{14}{28}] which leaves no place in n6 for both (28)
-> 8(2)r6c8 from [17] or [35]

4! n8 (and a bit of n9)
n8 = 13(2) + 16(3) + H16(4)
-> At least two of (123) in H16(4)
-> H16(4) not {1456}
Since neither of (48) in r78c4 and r78c4 is min +7 -> H16(4) not {1348}
Since r8c4 not from (57) -> H16(4) not {1357}
-> H16(4) must contain a 2
Since r8c4 from (1236) and r78c4 is min +7 -> 8(2)r6c4 cannot be [62]
IOD n9 -> r7c56 = r7c8 + 2
-> 2 not in r7c56
-> r8c4 = 2, r8c3 = 8

5. -> (Innies n89) r7c48 = {57}
-> (Remaining Innies n7) r7c23 = {49}
-> r7c48 cannot be [75] since that leaves no solution for 15(4)r7c5
-> r7c48 = [57]
-> r6c48 = [31]

6. r7c56 from {18} or {36}
Also 9(2)n9 from [81] or {36}
Those two 9(2)s cannot have the same values so between them they are {1368}
-> r78c7 (= remaining innies n9) = [24]
-> 12(3)n6 = {246}
-> r456c7 = {358}
7 in n3 not in 14(2) or 38(8)
-> (HS 7 in n3) r3c7 = 7
-> remaining cells in 29(6) = [r3c8,r6c6] = {24}

7. r234c6 has the same three values as in 14(2)n1 and r3c8
I.e., be from (59)|(68) and 2|4
Innies n12 = r3c2 + r23c6 = +14(3)
-> r23c6 cannot be +14
-> One of the values from 14(2) must be in r4c6
-> Whichever of (24) is in r3c8 must also be in r2c6
-> r34c6 = H14(2)

8. Remaining IOD n4 -> r4c2 + 2 = r4c4
Since r4c4 is max 8 -> r4c2 is max 6
-> r3c2 is min 3
Since r3c2 is min 3, r3c6 from (5689), r3c8 from (24), and r3c268 = +14(3) -> r3c268 = [482] or [392]
i.e., r3c8 = 2
-> r2c6 = 2 and r6c6 = 4

9. -> (HS 4 in n8) 13(2)n8 = {49}
-> r8c8 = 9

10. Since 14(2)n3 contains one of (56) -> 11(2)n2 not {56}
Also 2 in r2c6 -> 11(2)n2 not {29}
-> Both (59) in c6 only in r345c6
-> r34c6 = [95]
-> 14(2)n3 = [95]
Also 9(2)r3c2 = [36]
Also (remaining innies n2) r3c45 = [15]
-> r23c3 = [96]
Also (Innies n5) r4c4 = 8
-> 15(2)n4 = [78]
Also r456c3 = [{13}5]
Also r7c23 = [94]
Also 15(3)n4 = [492]
etc.


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