Texas Jigsaw Killer 27

Handmade <a href="http://www.sudocue.net/jigsawkiller.php">Killer puzzles</a> with 100% irregularity warrantee.<br>If you can handle these monsters, we'd like to know how you did it.
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mhparker
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Posts: 345
Joined: Sat Jan 20, 2007 10:47 pm
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Texas Jigsaw Killer 27

Post by mhparker »

This was another very enjoyable jigsaw killer to do on paper. Thanks, Ruud.

In contrast to Ruud's warning that the solving path was "long, very long", the puzzle could actually be solved pretty quickly.

Here's the walkthrough:


Texas Jigsaw Killer 027

Nonet layout:

111123333
114122333
144522236
144552236
447555266
487755669
487775669
888779699
888879999

1. Preliminaries:

a) 5/2 cage at R1C8 - no 5,6,7,8,9
b) 20/3 cage at R2C5 - no 1,2
c) 20/3 cage at R2C8 - no 1,2
d) 8/3 cage at R3C6 = {1(25|34)} -> no 1 elsewhere in N2
e) 15/2 cage at R4C1 = {69|87}
f) 9/3 cage at R4C5 - no 7,8,9
g) 8/2 cage at R4C9 - no 4,8,9
h) 10/2 cage at R5C1 - no 5
i) 19/3 cage at R5C2 - no 1
j) 20/3 cage at R6C6 - no 1,2
k) 13/2 cage at R6C8 - no 1,2,3
l) 20/3 cage at R7C7 - no 1,2
m) 10/3 cage at R7C9 - no 8,9
n) 10/2 cage at R9C1 - no 5

2. Innies/outies:

a) Outies N1: R1C5+R4C2 = 15/2 = {69|87} -> no 2,3,4,5 in R1C5
b) Outies N3: R3C9+R5C8 = 8/2 -> no 4,8,9
c) Outies N8: R5C2+R7C1 = 9/2 -> no 9
d) Outies N9: R6C8+R9C5 = 13/2 -> no 1,2,3 in R9C5
e) Innies N48: R4C23 = 11/2 -> no 1 in R4C3
f) Outies N12: R4C2+R5C6 = 11/2 -> no 1 in R5C6 -> no 9 in 13/3 cage at R4C7
g) From steps 2e) and 2f) above, we can conclude that R4C3 = R5C6 (common cell, matching cage sums)
-> no 9 in R4C3
h) Innies N36: R6C78 = 9/2 -> {36|45} (1,2 not available)
i) Outies N79: R5C4+R6C8 = 9/2 -> no 9 in R5C4
j) Outies C9: R126C8 = 11/3 -> no 9 in R2C8
k) Innies N7: R56C3+R9C5 = 19/3 -> no 1 in R56C3
l) Outies C12: R123C3 = 19/3 -> no 1
m) Outies C89: R789C7 = 20/3 -> no 1,2 in R9C7
n) Innies C9: R1236C9 = 27/3 = {(37|46)89} -> no 1,2,5
o) Outies N679: R5C4+R67C6 = 20/3 -> no 1,2 in R5C4
p) Innies R1234: R4C579 = 9/3 (no eliminations currently possible)
q) Outies C1: R489C2 = 14/3 (no eliminations currently possible)
r) Innies C6789: R289C6 = 17/3 (no eliminations currently possible)
s) Innies C89: R789C8 = 18/3 (no eliminations currently possible)
t) Innie/outie difference C89: R9C7 - R7C8 = 0 -> R9C7 = R7C8

3. {89} in N6 locked in 20/3 cage at R7C7 = {389} -> no 3,8,9 elsewhere in N6
4. No 3 in 20/3 cage at R2C8
5. {12} in N6 locked in 8/2 cage at R4C9 and hidden 8/2 cage R3C9+R5C8 (see step 2b) = {{6,2},{7,1}}
-> R3C9 = {67} and R5C8 = {12}, no 6 in R6C78 = {45}
-> no 4,5 elsewhere in R6 or N6, R6C9 = {89}, R67C6 = {6789}, R9C5 = {89} (see step 2d), no 6 in R5C1

6. 5 in C9 now locked in 10/3 cage at R7C9 = {(14|23)5} -> no 6,7
7. R34C8 (14/2 or 15/2) = {59|68|69|78} -> no 1,2,3,4

8. 5/2 cage R1C89 = [14|23] -> no 3,4 in R1C8
9. 20/3 cage R2C89+R3C9 = [596|587|497] -> R2C8 = {45}, R2C9 = {89}

10. Naked pair on {12} in C8 at R15C8 -> no 1,2 in R89C8
11. Naked pair on {45} in C8 at R26C8 -> no 4,5 in R89C8

12. R26C8 = {45} = 9/2 -> R1C8 = 2 (see step 2j) -> R1C9 = 3, R5C8 = 1 -> R3C9 = 7 (see step 2b)
-> 8/2 cage at R45C9 = {26} -> 10/3 cage at R7C9 = {145} -> no 1,4,5 elsewhere in N9

13. 1 in N3 locked in 12/3 cage at R1C6 = {1(47|56)} -> no 8,9
14. 2 in N9 locked in C6 -> 17/3 cage at R8C6 = {2(69|78)} -> no 3, no 2 elsewhere in C6

15. R4C9 = {26} -> innies R1234 (R4C579) = {126} (see step 2p) -> no 1,2,6 elsewhere in R4
-> 15/2 cage at R4C1 = {78} -> no 7,8 elsewhere in R4, R1C5 = {78} (see step 2a)

16. Naked single R4C8 = 9 -> R3C8 = 6
17. Naked single R2C9 = 8 -> R2C8 = 5
18. Naked single R6C8 = 4 -> R6C9 = 9, R9C5 = 9 (see step 2d)
19. Naked single R6C7 = 5
20. Hidden single in R5 at R5C1 = 9 -> R6C1 = 1
21. Hidden single in R3 at R3C4 = 9
22. Hidden single in C6 at R2C6 = 9
23. Hidden single in R4 at R4C5 = 1

24a. R5C6 = R4C3 = {34} (see steps 2e and 2g)
24b. 16/3 cage at R3C4 = {349} -> no 5 in R4C4 -> {34} in R4 locked in R4C34
-> no 3,4 elsewhere in R4 -> Naked single R4C6 = 5 -> R3C6 = 1, R3C7 = 2

25. Naked single R4C7 = 6 -> R4C9 = 2 -> R5C9 = 6
26. Hidden single in C6 at R5C6 = 3 -> R5C7 = 4
27. Naked single R4C4 = 4 -> R4C3 = 3 -> R4C2 = 8 (see step 2e) -> R4C1 = 7, R1C5 = 7 (see step 2e)

28. Naked single R1C6 = 4 -> R1C7 = 1 -> R2C7 = 7
29. Naked single R2C5 = 3 -> R3C5 = 8
30. Hidden single in R3 at R3C1 = 3
31. Hidden single in N4 at R5C2 = 7 -> R7C1 = 2 (see step 2c)
32. Hidden single (in 15/3 cage at R2C3) R2C3 = 6
33. Naked single R2C1 = 4 -> R1C1 = 5

Now we're on the way home...
Last edited by mhparker on Fri May 04, 2007 5:09 pm, edited 1 time in total.
Cheers,
Mike
mhparker
Grandmaster
Grandmaster
Posts: 345
Joined: Sat Jan 20, 2007 10:47 pm
Location: Germany

Post by mhparker »

Hi folks,

Please note that there was a logic error in the above walkthrough at step 24, which I have now corrected.
Cheers,
Mike
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