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 Post subject: Assassin 307
PostPosted: Thu Jan 15, 2015 2:28 pm 
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Grand Master
Grand Master

Joined: Wed Apr 30, 2008 9:45 pm
Posts: 552
Assassin 307

Happy New Year

Just a serendipity one, SS gives it 1.30.


Image

JS Code:
3x3::k:3873:3873:3074:3074:3587:2308:2308:2309:2309:3873:9250:9250:3074:3587:3587:1799:1799:2824:4873:9250:9250:9250:6922:1291:1291:3084:2824:4873:4873:9250:6922:6922:6413:2062:3084:2063:3344:3344:6922:6922:6413:6413:2062:3345:2063:2066:3344:6179:6413:6413:4116:4116:3345:3871:2066:2838:6179:6179:6179:4116:6944:3871:3871:2841:2838:2074:2074:3099:3099:6944:6944:6944:2841:1820:1820:2589:2589:3358:3358:6944:6944:

Solution:
831694572
479523168
526871493
684957231
392418657
715362984
168745329
257139846
943286715


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 Post subject: Re: Assassin 307
PostPosted: Thu Jan 15, 2015 11:43 pm 
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Grand Master
Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1658
Location: Lethbridge, Alberta, Canada
Thanks HATMAN for another killer, and Happy New Year to everyone on the forum!

This proved to be a very easy puzzle, about the level of one of Ruud's early Assassins. Maybe the serendipity was that, despite some parts of the cage pattern looking complex, it happened to come out easily.
I wonder what I found that Sudoku Solver couldn't manage:
Possibly something in N6? Step 5.

Here is my walkthrough for Assassin 307:
Prelims

a) R1C67 = {18/27/36/45}, no 9
b) R1C89 = {18/27/36/45}, no 9
c) R2C78 = {16/25/34}, no 7,8,9
d) R23C9 = {29/38/47/56}, no 1
e) R3C67 = {14/23}
f) R34C8 = {39/48/57}, no 1,2,6
g) R45C7 = {17/26/35}, no 4,8,9
h) R45C9 = {17/26/35}, no 4,8,9
i) R56C8 = {49/58/67}, no 1,2,3
j) R67C1 = {17/26/35}, no 4,8,9
k) R78C2 = {29/38/47/56}, no 1
l) R89C1 = {29/38/47/56}, no 1
m) R8C34 = {17/26/35}, no 4,8,9
n) R8C56 = {39/48/57}, no 1,2,6
o) R9C23 = {16/25/34}, no 7,8,9
p) R9C45 = {19/28/37/46}, no 5
q) R9C67 = {49/58/67}, no 1,2,3
r) 19(3) cage at R3C1 = {289/379/469/478/568}, no 1

1. 45 rule on N3 3 innies R1C7 + R3C78 = 18 = {189/279/369/378/459/468} (cannot be {567} because R3C7 only contains 1,2,3,4)
1a. R3C7 = {1234} -> no 1,2,3,4 in R1C7 + R3C8, clean-up: no 5,6,7,8 in R1C6, no 8,9 in R4C8

2. 45 rule on R89 2 outies R7C27 = 9, no 9 in R7C2, no 8,9 in R7C7, clean-up: no 2 in R8C2

3. 45 rule on N9 2(1+1) outies R6C9 + R9C6 = 10, min R9C6 = 4 -> max R6C9 = 6

4. Hidden killer pair 8,9 in R56C8 and R6C7 for N6, each can only contain one of 8,9 -> R6C7 = {89}, R56C8 = {49/58}, no 6,7
4a. 16(3) cage at R6C6 cannot contain both of 8,9, R6C7 = {89} -> no 8,9 in R67C6
4b. R34C8 = {57}/[93] (cannot be [84] which clashes with R56C8), no 8 in R3C8, no 4 in R4C8

5. Hidden killer pair 2,6 in R45C7, R45C9 and R6C9 for N6, R45C7 and R45C9 must both contain both or neither of 2,6, R6C9 cannot contain both of 2,6 -> no 2,6 in R6C9, clean-up: no 4,8 in R9C6 (step 3), no 5,9 in R9C7

6. R1C7 + R3C78 (step 1) = {189/279/369/378/459} (cannot be {468} because R3C8 only contains 5,7,9)
6a. 9 of {459} must be in R3C8 -> no 5 in R3C8, clean-up: no 7 in R4C8
6b. Killer pair 5,9 in R34C8 and R56C8, locked for C8, 5 also locked for N6, clean-up: no 4 in R1C9, no 2 in R2C7, no 3 in R45C7, no 3 in R45C9, no 5 in R9C6 (step 3), no 8 in R9C7

7. Naked quad {1267} in R45C79, locked for N6, clean-up: no 9 in R9C6 (step 3), no 4 in R9C7
7a. Naked pair {67} in R9C67, locked for R9, clean-up: no 4,5 in R8C1, no 1 in R9C23, no 3,4 in R9C45

8. 45 rule on C89 3 outies R278C7 = 12 = {138/147/246/345} (cannot be {129/156/237} which clash with R45C7), no 9

9. R6C7 = 9 (hidden single in C7), clean-up: no 4 in R56C8
9a. Naked pair {58} in R56C8, locked for C8 -> R4C8 = 3, R3C8 = 9, R6C9 = 4, R9C6 = 6 (step 3), R9C7 = 7, clean-up: no 2 in R1C6, no 1,6 in R1C9, no 4 in R2C7, no 2,7 in R23C9, no 1 in R45C7, no 2 in R8C3
9b. Naked pair {26} in R45C7, locked for C7 and N6, clean-up: no 3 in R1C6, no 1 in R2C8, no 3 in R3C6
9c. Naked pair {17} in R45C9, locked for C9, clean-up: no 2 in R1C8

10. R1C7 + R3C78 (step 6) = {189/459}, no 3, clean-up: no 2 in R3C6
10a. Naked pair {14} in R3C67, locked for R3
10b. Naked pair {14} in R13C6, locked for C6 and N2, clean-up: no 8 in R8C5
10c. R1C89 = [18/45/72] (cannot be [63] which clashes with R23C9), no 3,6

11. R6C7 = 9 -> R67C6 = 7 = {25}, locked for C6, clean-up: no 7 in R8C5

12. Killer triple 1,2,4 in R9C23, R9C45 and R9C8, locked for R9, clean-up: no 7,9 in R8C1

13. 1 in N7 only in R7C13 + R8C3
13a. 45 rule on N7 3 innies R7C13 + R8C3 = 16 = {169/178}, no 2,3,4,5, clean-up: no 3,5,6 in R6C1, no 3,5 in R8C4
13b. 8,9 only in R7C3 -> R7C3 = {89}

14. R6C9 = 4 -> R7C89 = 11 = [29/65]
14a. Killer pair 2,5 in R7C6 and R7C89, locked for R7, clean-up: no 6,9 in R8C2

[Only just spotted …]
15. 45 rule on R12 3 innies R2C239 = 24 = {789} -> R2C9 = 8, R2C23 = {79}, locked for R2, N1 and 36(6) cage at R2C2, R3C9 = 3, R1C7 = 5 -> R1C6 = 4, R3C67 = [14], R1C9 = 2 -> R1C8 = 7, R2C678 = [316], R78C7 = [38], R7C8 = 2, R67C6 = [25], R7C9 = 9, R89C9 = [65], R7C3 = 8
15a. R8C34 = {17} (only remaining combination), locked for R8, R8C6 = 9 -> R8C5 = 3, R89C8 = [41], R8C1 = 2 -> R9C1 = 9, R8C2 = 5 -> R7C2 = 6

16. R2C1 = 4 (hidden single in R2) -> R1C12 = 11 = {38}, locked for R1 and N1, R3C2 = 2
16a. R1C3 = 1 (hidden single in R1), R8C34 = [71]
16b. R7C345 = 8{47} -> R6C3 = 5 (cage sum)

17. R3C1 = 5 (hidden single in N1) -> R4C12 = 14 = [68]

and the rest is naked singles.

Rating Comment:
I'll rate my walkthrough for A307 at 1.0. I used hidden killer pairs and a killer triple.


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 Post subject:
PostPosted: Fri Jan 16, 2015 6:20 pm 
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Grand Master
Grand Master

Joined: Mon Apr 21, 2008 9:44 am
Posts: 310
Location: MV, Germany
Thanks for the new Killer, HATMAN!

A307 Walkthrough:
1. R123 !
a) ! Innies+Outies N23: -23 = R1C3 - R3C458 -> R1C3 = 1; R3C458 = {789} locked for R3
b) Innies R12 = 24(3) = {789} locked for R2
c) Both 9(2) <> 8
d) 11(2) = [74/83/92]
e) 5,6 locked in R3C123 @ R3 for N1
f) 15(3) = 4{29/38} -> 4 locked for N1
g) 36(6) = 4789{26/35} -> R4C2 = 4
h) 12(2) = [75/93]
i) Hidden Single: R2C9 = 8 @ N3 -> R3C9 = 3, R3C8 = 9 @ N3 -> R4C8 = 3

2. C123 !
a) 36(6) = {246789} -> 2,6 locked for R3+N1; 9 locked for N1; R3C4 = 8
b) R3C1 = 5, R3C5 = 7
c) 19(3) = {568} -> 6,8 locked for R4+N4
d) Hidden Single: R7C3 = 8 @ C3
e) 13(3) = 1{39/57} -> 1 locked for N4
f) 8(2) @ C1 = [26/71]
g) 11(2) @ C1 = {29/47}
h) 7(2) = {25}/[43] since {16} blocked by R7C1 = (16)
i) ! Killer pair (24) locked in 11(2) @ C1 + 7(2) for N7
j) 11(2) @ C2 = {56} locked for C2+N7
k) R7C1 = 1 -> R6C1 = 7, R3C2 = 2, R9C2 = 4 -> R9C3 = 3, R8C3 = 7 -> R8C4 = 1

3. N68
a) 10(2) = {28} -> R9C4 = 2, R9C5 = 8
b) Hidden Single: R7C4 = 7 @ C4
c) 24(4) = {4578} since R6C3 <> 3,6 -> R6C3 = 5, R7C5 = 4
d) 13(2) = {67} -> R9C6 = 6, R9C7 = 7
e) 12(2) = {39} locked for R8+N8
f) R7C6 = 5
g) 15(3) = {249} -> R7C8 = 2, R7C9 = 9, R6C9 = 4
h) 8(2) @ C7 = [26] -> R4C7 = 2, R5C7 = 6
i) Hidden Single: R6C7 = 9 @ C7 -> R6C6 = 2

4. Rest is singles.

Rating:
1.0. I used IOD and a Killer pair.


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