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 Post subject: Assassin 287
PostPosted: Thu Mar 13, 2014 1:12 pm 
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Grand Master
Grand Master

Joined: Wed Apr 30, 2008 9:45 pm
Posts: 694
Location: Saudi Arabia
Assassin 287

Another serendipity one. SS gives it 1.35 which might be a bit high, JS just uses a couple of small fishes.

I have a couple in reserve so I'll try and post again next week to give Ed a break.


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3x3::k:6145:6145:5378:5378:5379:5636:5636:5125:5125:6145:6145:5378:5379:5379:5379:5636:5125:5125:4102:4102:5378:3335:5379:2312:5636:4617:4617:1034:4102:5378:3335:3851:2312:5636:4617:2572:1034:5901:3854:3854:3851:3087:3087:6160:2572:2065:5901:5901:3854:2066:3087:6160:6160:3859:2065:1556:5901:4885:2066:4374:6160:1559:3859:4888:1556:4885:4885:1817:4374:4374:1559:3354:4888:4888:2843:2843:1817:2332:2332:3354:3354:


941326875
837195462
526847391
394572186
175689234
268431957
612953748
453718629
789264513


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PostPosted: Fri Mar 14, 2014 7:52 pm 
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Grand Master
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Joined: Mon Apr 21, 2008 9:44 am
Posts: 310
Location: MV, Germany
Despite this Killer not being too hard, it took me quite some time to find the critical move (step 2e). Therefore thank you HATMAN for this challenging Assassin!

A287 Walkthrough:
1. C456
a) Innie C1234 = R2C4 = 1
b) Outie C5 = R2C6 = 5
c) 1,5 locked in 8(2) + 7(2) = 15(4) @ C5 = 15{27/36} -> 7(2) <> {34}, 8(2) <> {26}

2. C123 !
a) 4(2) = {13} locked for C1+N4
b) 8(2) = {26} locked for C1
c) ! 19(3) <> 5 since {568} blocked by Killer triple (256) in R7C1 + 6(2)
d) 5 locked in R13C1 @ C1 for N1
e) ! R789C3 can only have one of (15) because of Killer pair (15) in 21(5)
f) Hidden Killer pair (15) in 6(2) for N7 since R789C3 can only have one of (15) -> 6(2) = {15} locked for C2+N7
g) Innies C12 = 13(2) = {49/67}
h) Outies C12 = 10(2) <> 4,5,6,9 since (46) is a Killer pair of Innies C12

3. R6789+C89
a) Outies C89 = 16(2) = {79} locked for C7+24(4)
b) Innies C89 = 8(2) = {26/35}
c) 4 locked in Outies R89 @ R7 = 17(4) = 14{39/57} since R7C2 = (15) and {2456} blocked by R7C1 = (26) -> 1 locked for R7
d) Killer pair (79) locked in Outies R89 + R7C7 for R7
e) 8(2) = {35} locked for C5
f) 7(2) = {16} locked for C5+N8
g) 15(2): R6C9 <> 6,8
h) Naked pair (79) locked in R6C79 for R6+N6
i) Outies C12 = 10(2) = {28} locked for C3
j) Hidden Single: R6C6 = 1 @ R6

4. R456
a) Outies C1234 = 13(3) = {139/148/238/346} <> 7 and since R5C1 = (13)
b) 15(2) @ N5 = {78} -> R5C5 = 8, R4C5 = 7
c) 12(3) = [65/92]1
d) Killer pair (25) locked in Innies C89 + R5C7 for N6
e) 10(2) = {46} locked for C9+N6
f) Innies C89 = 8(2) = {35} locked for C8+N6
g) R7C9 = 8 -> R6C9 = 7, R5C7 = 2 -> R5C6 = 9,
h) Innies C12 = 13(2) = {67} -> R6C2 = 6, R5C2 = 7
i) Innies R1234 = 9(2) = [36] -> R4C1 = 3, R4C9 = 6

5. R123
a) 21(5) @ C5 = {12459} locked for N2
b) 13(2) = [85] -> R3C4 = 8, R4C4 = 5
c) 9(2) = [72] -> R4C6 = 2, R3C6 = 7
d) 22(5) = {13468} -> 4 locked for N3
e) 18(3) = {189} since R4C8 = (18) -> R4C8 = 8; 1,9 locked for R3+N3
f) 5 locked in 16(3) @ R3 = {259} -> R3C1 = 5, R3C2 = 2, R4C2 = 9

6. R789
a) R6C5 = 3, R6C4 = 4, R4C3 = 4
b) 11(2) = {29} -> R9C3 = 9, R9C4 = 2
c) Innies N9 = 18(3) <> 1
d) 9(2) <> 8

7. Rest is singles.

Rating:
1.25. I used a Killer triple combo blocker and a Hidden Killer pair.


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 Post subject: Re: Assassin 287
PostPosted: Tue Mar 18, 2014 9:11 am 
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Grand Master
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Joined: Wed Apr 16, 2008 1:16 am
Posts: 1043
Location: Sydney, Australia
Great solution Afmob! I never gave that 2e area even 1 minute worth of looking. Instead, I had to work a lot harder and used a (short) contradiction move (step 7). Thanks HATMAN for a really challenging puzzle. Look forward to another one from you to follow up. What do you mean by a 'serendipity' puzzle? [edit: HATMAN answered my question in the intro to the next Assassin. Many thanks to Andrew and Afmob for some typos and clarifications]

A287 Walkthrough
21 steps:
Preliminaries
Cage 4(2) n4 - cells ={13}
Cage 6(2) n9 - cells only uses 1245
Cage 6(2) n7 - cells only uses 1245
Cage 15(2) n5 - cells only uses 6789
Cage 15(2) n69 - cells only uses 6789
Cage 7(2) n8 - cells do not use 789
Cage 8(2) n58 - cells do not use 489
Cage 8(2) n47 - cells do not use 489
Cage 13(2) n25 - cells do not use 123
Cage 9(2) n89 - cells do not use 9
Cage 9(2) n25 - cells do not use 9
Cage 10(2) n6 - cells do not use 5
Cage 11(2) n78 - cells do not use 1
Cage 19(3) n78 - cells do not use 1
Cage 19(3) n7 - cells do not use 1

1. "45" on c1234: 1 innie r2c4 = 1
1a. "45" on c6789: 1 innie r2c6 = 5
1b. no 4 in 9(2)r3c6
1c. no 4 in r9c7
1d. no 8 in r4c6

2. 4(2)n4 = {13} only: both locked for c1 and n4
2a. -> 8(2)r67c1 = {26} only: both locked for c1

3. "45" on c12: 2 outies r67c3 = 10 (no 5)
3a. no 7,9 in r7c3
3b. r67c3 = 10 -> h13(2)r56c2 (no 2)(cage sum)

4. "45" on c89: 2 outies r67c7 = 16 = {79} only: both locked for c7 and for 24(4)
4a. no 7,9 in r56c8
4b. r67c7 = 16 -> r56c8 = 8 (cage sum) = {26/35}(no 1,4,8) = [2/5..]
4c. no 2 in r9c6

5. 6(2)r7c8 = {15/24} = [2/5,,]
5a. ->with step 4b, 2 & 5 in r5678c8: locked for c8 (Killer pair)

6. "45" on n9: 4 innies r7c79+r89c7 = 26 -> no 1 in r89c7
6a. no 8 in r9c6

This key step is a contradiction move so not easy to find.
7. 6(2)n9 = {15/24} = [1/4,2/5..] -> 13(3)n9: {148/256} blocked
7a. 13(3)n9 = {139/157/238/247/346} = [2/4/7/9..]
7b. -> r7c79+r78c8 can't be {79}+{24}
7c. -> [69] blocked from r67c9 since it forces r5678c8 = {35}+{15}
7d. ->r6c9 = (789)
7e. ->r7c9 = (678)

8. deleted

9. r6c79 can't be [98] because can't be [77] in r7c79 (Combo crossover clash; CCC)
9a. -> r6c79 = [78/79/97]
9b. -> 7 must be in r6c79: locked for r6 and n6
9c. no 3 in 10(2)n6
9d. no 1 in r7c5
9e. no 3 in r7c3 (h10(2)r67c3)
9f. no 6 in r5c2 (h13(2)r56c2)

10. "45" on r6789: remembering h10(2)r67c3 and h16(2)r67c7 -> 4 innies r6c2468 = 16
10a. but {2356} blocked by r6c1 = (26)
10b. = {1249/1258/1348/1456}
10c. must have 1 -> r6c6 = 1
10d. no 8 in 9(2)r3c6
10e. no 7 in r7c5
10f. no 8 in r9c7

Missing routine clean-up from here
11. 1 in c5 only in 7(2)n8 = {16} only: both locked for c5 and n8
11a. -> 8(2)r6c5 = {35} only: both locked for c5
11b. -> 15(2)n5 = {78} only: both locked for c5 and n5


12. "45" on r1234: 3 innies r4c159 = 16: must have 1/3 for r4c1 and 7/8 for r4c5 = {178/358/367}(no 2,4,9)
12a. 1 in {178} must be in r4c1 -> no 1 in r4c9
12b. r5c9 = (24)

13. 10(2)n6 = [64/82] = [2/6..]
13a. -> {26} blocked from h8(2)r56c8
13b. -> r56c8 = {35} only: both locked for n6 and c8
13c. -> 6(2)n9 = {24} only: both locked for n9 and 4 for c8

14. r6c6 = 1 -> r5c67 = 11 (cage sum) = [38/92]

15. [82] blocked from 10(2)n6 by r5c7 = (28)
15a. -> r56c9 = [64]
15b. -> 15(2)r6c9 = {78} only: both locked for c9
15c. r4c9 = 6 -> r4c15 = 10 (h16(3)r4c158) = [37]
15d. r5c5 = 8

16. Naked pair {35} in r6c58: both locked for r6

17. 6 in r5 only in 15(3)r5c3 -> no 6 in r6c4 (same cage)
17a. -> Hidden single 6 in n5 ->r5c4 = 6
17b. r34c6 = [72], r5c67=[92] (cage sum)

18. r6c4 = 4, r5c3 = 5 (cage sum)
18a. r56c2 = [76] (h13(2)), r67c1 = [26]

19. 19(3)n7 = {289/379/479}(no 5)

20. 5 in n7 only in 6(2) = {15} only: both locked for c2 and 1 for n7

21. h10(2)r67c3 = [82] only permutation

etc
Cheers
Ed


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 Post subject: Re: Assassin 287
PostPosted: Tue Mar 18, 2014 10:30 pm 
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Grand Master
Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1894
Location: Lethbridge, Alberta, Canada
Ed wrote:
Great solution Afmob! Thanks HATMAN for a really challenging puzzle. Look forward to another one from you to follow up.
I agree with Ed on all of that. I also found it a hard puzzle, even though I didn't use technically difficult steps.

Ed wrote:
I never gave that 2e area even 1 minute worth of looking.
That's a minute more than I did! Even though I've got my own table of combinations, I only look at it when I feel I need to or to check combos with 4 or more candidates. I never thought of looking at the combos for that cage.

Ed wrote:
What do you mean by a 'serendipity' puzzle?
I think it means one where one happens across the key step(s) by chance. The previous time HATMAN posted a 'serendipity' puzzle I felt I'd done that; this time I certainly didn't.

Here is my walkthrough for Assassin 287:
Thanks Afmob for your comments and corrections.

Prelims

a) R34C4 = {49/58/67}, no 1,2,3
b) R34C6 = {18/27/36/45}, no 9
c) R45C1 = {13}
d) R45C5 = {69/78}
e) R45C9 = {19/28/37/46}, no 5
f) R67C1 = {17/26/35}, no 4,8,9
g) R67C5 = {17/26/35}, no 4,8,9
h) R67C9 = {69/78}
i) R78C2 = {15/24}
j) R78C8 = {15/24}
k) R89C5 = {16/25/34}, no 7,8,9
l) R9C45 = {29/38/47/56}, no 1
m) R9C67 = {18/27/36/45}, no 9
n) 19(3) cage at R7C4 = {289/379/469/478/568}, no 1
o) 19(3) cage at R8C1 = {289/379/469/478/568}, no 1

1. Naked pair {13} in R45C1, locked for C1 and N4, clean-up: no 5,7 in R67C1
1a. Naked pair {26} in R67C1, locked for C1

2. 45 rule on C1234 1 innie R2C4 = 1, clean-up: no 8 in R4C6

3. 45 rule on C6789 1 innie R2C6 = 5, clean-up: no 4 in R34C6, no 8 in R4C4, no 4 in R9C7

4. 45 rule on C5 3 innies R123C5 = 15 = {249/348} (cannot be {267} which clashes with R45C5), no 6,7, 4 locked for C5 and N2, clean-up: no 9 in R4C4, no 3 in R89C5

5. R67C5 = {17/35} (cannot be {26} which clashes with R89C5), no 2,6

6. 45 rule on C12 2 outies R67C3 = 10 = {28/46}/[73/91], no 5, no 7,9 in R7C3
6a. 45 rule on C12 2 innies R56C2 = 13 = {49/58/67}, no 2

7. 45 rule on C89 2 outies R67C7 = 16 = {79}, locked for C7 and 24(4) cage at R5C8, no 7,9 in R56C8, clean-up: no 2 in R9C6
7a. 45 rule on C89 2 innies R56C8 = 8 = {26/35}
7b. Killer pair 2,5 in R56C8 and R78C8, locked for C8
7c. 1 in R6 only in R6C56, locked for N5, clean-up: no 8 in R3C6

8. 45 rule on R1234 3 innies R4C159 = 16 = {169/178/349/367} (cannot be {268} because R4C1 only contains 1,3), no 2, clean-up: no 8 in R5C9
8a. R4C1 = {13} -> no 1,3 in R4C9, clean-up: no 7,9 in R5C9

9. 45 rule on R1234 3 outies R5C159 = 13 = {139/148/238/346} (cannot be {247} because R5C1 only contains 1,3), no 7, clean-up: no 8 in R4C5
9a. 4 of {346} must be in R5C9 -> no 6 in R5C9, clean-up: no 4 in R4C9

10. 45 rule on N9 4 innies R789C7 + R7C9 = 26 = {2789/3689/4679/5678}, no 1, clean-up: no 8 in R9C6

11. 17(3) cage at R7C6 = {269/278/359/368/458/467} (cannot be {179} because no 1,7,9 in R8C7), no 1
11a. 5 of {458} must be in R8C7, 4 of {467} must be in R78C6 (R78C6 cannot be {67} which clashes with R34C6) -> no 4 in R8C7
11b. R789C7 + R7C9 (step 10) = {2789/3689/5678}, 8 locked for N9

12. 45 rule on R89 4 outies R7C2468 = 17 = {1259/1349/1358/1457/2348/2357} (cannot be {1268/2456} which clash with R7C1, cannot be {1367} because two of 1,2,4,5 are required in R7C28), no 6 in R7C46

13. R56C2 (step 6a) = {49/58/67}, R67C3 (step 6) = {28/46}/[73/91],
13a. 23(4) cage at R5C2 cannot be {58}{46} which clashes with R7C1 + R78C2, no 4,6 in R67C3

14. 4 in R7 only in R7C2468 (step 12) = {1349/1457/2348}
14a. 3,8 of {2348} must be in R7C46 -> no 2 in R7C46
14b. 3 must be in R7C46 + R7C5, locked for R7 and N8, clean-up: no 7 in R6C3 (step 6), no 8 in R9C3, no 6 in R9C7
14c. 1 must be in R7C28 + R7C3, locked for R7, clean-up: no 7 in R6C5

15. R789C7 + R7C9 (step 11) = {2789/3689/5678}
15a. 6 of {5678} must be in R8C7 (R7C79 cannot be [76] which would put two 9s in R6C79), no 5 in R8C7
15b. 6 of {3689} must be in R7C9 (R7C79 cannot be [98] which would put two 7s in R6C79)
15c. 17(3) cage at R7C6 (step 11) = {269/278/368} (cannot be {467} = {47}6 which clashes with R9C67 = [45] because 6 in R8C7 must be part of R789C7 + R7C9 = {5678}, steps 15a and 15b), no 4 in R78C6
15d. 9 of {269} must be in R7C6 -> no 9 in R8C6

[I ought to have spotted this after step 14.]
16. R7C2468 (step 14) = {1349/1457/2348}
16a. Hidden killer pair 3,5 in R7C2468 and R7C5 for R7, R7C2468 contains one of 3,5 -> R7C5 = {35}, clean-up: no 1 in R6C5
16b. Naked pair {35} in R67C5, locked for C5, clean-up: no 2 in R89C5
16c. Naked pair {16} in R89C5, locked for C5 and N8, clean-up: no 9 in R45C5, no 5 in R9C3, no 3,8 in R9C7

17. R45C8 = [78], clean-up: no 6 in R3C4, no 2 in R3C6, no 3 in R5C9, no 5 in R6C2 (step 6a)
17a. Naked triple {249} in R123C5, locked for N2, clean-up: no 4 in R4C4
17b. R4C159 (step 8) contains 7 = {178/367} -> R4C9 = {68}, clean-up: no 1 in R5C9
17c. Killer pair 6,8 in R4C9 and R67C9, locked for C9
17d. R56C8 (step 7a) = {35} (cannot be {26} which clashes with R45C9), locked for C8 and N6, clean-up: no 1 in R78C8
17e. Naked pair {24} in R78C8, locked for C8 and N9 -> R9C7 = 5, R9C6 = 4, clean-up: no 6,7 in R9C3, no 7 in R9C4

18. R6C6 = 1 (hidden single in R6) -> R5C67 = 11 = [92], R5C9 = 4 -> R4C9 = 6, R4C4 = 5 -> R3C4 = 8, R67C5 = [35], R4C6 = 2 -> R3C6 = 7, R56C4 = [64], R5C3 = 5 (cage sum), R5C2 = 7, R6C2 = 6 (step 6a), R67C1 = [26], R1C46 = [36], R78C6 = [38], R8C7 = 6
[Routine clean-ups omitted.]

19. R7C2468 (step 14) = {1349} (only remaining combination) -> R7C4 = 9, R7C2 = 1 -> R8C2 = 5, R78C8 = [42], R9C4 = 2, R8C4 = 7, R8C3 = 3 (cage sum)

20. R7C79 = [78] -> R6C79 = [97], R67C3 = [82], R9C3 = 9, R8C1 = 4, R4C3 = 4, R4C2 = 9, R3C1 = 5, R3C2 = 2 (cage sum)

[Steps 20 and 21 simplified and combined; step 22 deleted, Afmob pointed out that it’s naked singles after my original step 21.]

and the rest is naked singles.

Rating Comment:
I'll rate my walkthrough for A287 at least Hard 1.25. I haven't taken account of step 15 in making my rating, since it was either unnecessary or could have been done more simply later.


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