SudokuSolver Forum

A forum for Sudoku enthusiasts to share puzzles, techniques and software
It is currently Fri Apr 19, 2024 8:06 am

All times are UTC




Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: Ix Killer 11
PostPosted: Sun Mar 10, 2019 10:30 am 
Offline
Addict
Addict

Joined: Sat Mar 28, 2015 8:36 pm
Posts: 24
Here is another killer, hope you find it enjoyable. This time it is an X with two empty chutes.

ImageImage
SS Score: 1.55

Code: paste into solver:
3x3:d:k:0000:0000:0000:3077:3077:4360:2818:2818:3335:0000:0000:0000:3077:4360:4360:2818:3335:4867:0000:0000:0000:3846:4365:4365:4365:4365:4867:0000:0000:0000:3846:3072:1804:4365:3849:4867:0000:0000:0000:2826:1547:3072:1804:3849:3849:0000:0000:0000:1547:2826:2305:2305:4100:4100:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:0000:



Solution:
289173456
163495278
475826319
896731542
712549683
534268197
348617925
651982734
927354861


Cheers.


Top
 Profile  
Reply with quote  
 Post subject: Re: Ix Killer 11
PostPosted: Wed Mar 13, 2019 7:42 pm 
Offline
Grand Master
Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1894
Location: Lethbridge, Alberta, Canada
Thanks ixsetf. Very impressive to produce a killer with so much empty space!

Here is my walkthrough for Ix Killer 11:
This is a Killer-X

Prelims

a) 13(2) cage at R1C9 = {49/58/67}, no 1,2,3
b) R34C4 = {69/78|
c) 12(2) cage at R4C5 = {39/48/57}, no 1,2,6
d) 7(2) cage at R4C6 = {16/25/34}, no 7,8,9
e) 11(2) cage at R5C4 = {29/38/47/56}, no 1
f) 6(2) cage at R5C5 = {15/24}
g) R6C67 = {18/27/36/45}, no 9
h) R6C89 = {79}
i) 11(3) cage at R1C7 = {128/137/146/236/245}, no 9
j) 19(3) cage at R2C9 = {289/379/469/478/568}, no 1
k) 17(5) cage at R3C5 = {12347/12356}, no 8,9

1. Naked pair {79} in R6C89, locked for R6 and N6, clean-up: no 2,4 in R5C4, no 2 in R6C67
1a. 19(3) cage at R2C9 = {289/469/478/568} (cannot be {379} which clashes with R6C9), no 3

2. 45 rule on N23 3 outies R4C479 = 14
2a. Min R4C47 = 7 -> no 8 in R4C9
2b. 19(3) cage at R2C9 (step 1a) = {289/469/478/568}
2c. 2 of {289} must be in R4C9 -> no 2 in R23C9

3. 45 rule on N6 4 innies R4C79 + R56C7 = 14 = {1238/1256/1346/2345}
3a. R4C479 = 14 (step 2) = {149/167/239/257/347/356} (cannot be {158} = [815] which clashes with R4C6 + R5C7 = [52] using R4C79 + R56C7, cannot be {248} = 8{24} which clashes with R4C6 + R5C7 = [25/43] using R4C79 + R56C7), no 8 in R4C4, clean-up: no 7 in R3C3
3b. R4C479 = {149/167/239/257/347} (cannot be {356} = [635] which clashes with R4C6 + R5C7 = [34/52] using R4C79 + R56C7)
3c. R4C479 = {167/239/257/347} (cannot be {149} = [914] which clashes with R4C6 + R5C7 = [16/43] using R4C79 + R56C7)
3d. 7 of {167} must be in R4C4 -> no 6 in R4C4, clean-up: no 9 in R3C4

4. 45 rule on N2 3 innies R3C456 = 16 = 6{37}/8{17}/8{26}/8{35}, no 4
4a. 17(5) cage at R3C5 = {12347/12356}, R3C56 = {17/37}, 7 locked for R3
or R3C56 = {26/35} are only in {12356}
-> no 7 in R3C78
4b. R4C479 (step 3c) = {167/257/347} (cannot be {239} = [932] which clashes with R3C456 = 6{37} using R34C4 = 15), no 9
4c. R4C4 = 7 -> R3C4 = 8, 7 placed for D\, clean-up: no 5 in 12(2) cage at R4C5, no 3,4 in R6C5
4d. R4C4 = 7 -> R4C79 = 7 = [16/25/34/52], no 4,6 in R4C7
4e. 9 in N5 only in 12(2) cage at R4C5 = {39} or 11(2) cage at R5C4 = [92] -> 11(2) cage = [56/65/92] (cannot be [38], locking-out cages), no 3,8
4f. Killer pair 2,5 in 11(2) cage and 6(2) cage at R5C5, locked for N5, clean-up: no 2,5 in R5C7, no 4 in R6C7

5. 45 rule on N5 2 remaining outies R56C7 = 7 = [16/43/61], no 3 in R5C7, no 5,8 in R6C7, clean-up: no 4 in R4C6, no 1,4 in R6C6
5a. 1 in N5 only in R4C6 + R5C5 + R6C5, locked for D/

6. 45 rule on N2 3 outies R3C78 + R4C7 = 9 = {126/135/234}
6a. 19(3) cage at R2C9 (step 1a) = {289/469/478/568}
6b. Consider placements for 9 in N3
9 in 13(2) cage at R1C9 = {49}, locked for N3 and D/ => 6(2) cage at R5C5 = {15}, 5 locked for D/ => R3C7 = {236} => R3C78 + R4C7 = {126/135} with 3 of {135} in R3C7, no 3 in R4C7 => no 4 in R4C9 (step 4d) => 19(3) cage = {568}
or 9 in 19(3) cage = {289/469}
-> 19(3) cage = {289/469/568}, no 7
6c. Taking that first path further, 19(3) cage = {568} must be [856] (cannot be [865] which because R3C78 + R4C7 = {135} is inconsistent with R4C79 (step 4d) = [25]) -> no 5 in R24C9, clean-up: no 2 in R4C7 (step 4d)
6d. 17(5) cage at R3C5 = {12347/12356}, 2 locked for R3
6e. Consider permutations for R4C79 (step 4d) = [16/34/52]
R4C79 = [16] => R3C56 (step 4a) = {26/35} => 17(5) cage = {12356}, 5 locked for R3 => 19(3) cage = {49}6
or R4C79 = [34] => 19(3) cage = {469}
or R4C79 = [52] => 19(3) cage = {289}
-> 19(3) cage = {289/469}, no 5, 9 locked for C9 and N3, clean-up: no 4 in 13(2) cage at R1C9
6f. R6C89 = [97], clean-up: no 6 in R2C8

7. 19(3) cage at R2C9 (step 6e) = {289/469}
7a. Consider combinations for 11(2) cage at R5C4 = {56}/[92]
11(2) cage = {56} => 6(2) cage at R5C5 = {24}, R4C6 = 1 (hidden single in N5) -> R5C7 = 6
or 11(2) cage = [92] => 6(2) cage = {15}, locked for D/ => 13(2) cage at R1C9 = [67]
-> no 6 in R4C9, clean-up: no 1 in R4C7 (step 4d)
7b. 4 of 19(3) cage = {469} must be in R4C9 -> no 4 in R23C9
7c. Killer pair 6,8 in 13(2) cage at R1C9 and R23C9, locked for N3
7d. 17(5) cage at R3C5 = {12347/12356}, 1 locked for R3
7e. R3C78 + R4C7 (step 6) = {135/234}, 3 locked for 17(5) cage at R3C5, clean-up: no 5 in R3C56 (step 4a)
7f. R3C78 + R4C7 (step 6) = {135/234}, CPE no 3 in R12C7
7g. 1 of {135} must be in R3C8, 3 of {234} must be in R4C7 -> no 3,5 in R3C8
7h. 11(3) cage at R1C7 = {137/245}
7i. 3 of {137} must be in R1C8 -> no 1,7 in R1C8
7j. Consider placements for R4C7 = {35}
R4C7 = 3 => R56C7 (step 5) = {16}, locked for C7
or R4C7 = 5 => R3C8 = 1
-> 11(3) cage at R1C7 = {245} (only remaining combination), locked for N3, clean-up: no 8 in 13(2) cage at R1C9
7k. Naked triple [673] in R1C9 + R2C8 + R3C7, placed for D/
7l. R23C9 = [89], R3C8 = 1, R4C7 = 5 -> R4C9 = 2 (step 4d), R4C6 = 1 -> R5C7 = 6, R6C7 = 1 -> R6C6 = 8, placed for D\
7m. 12(2) cage at R4C5 = {39} (only remaining combination), locked for N5
7n. 6(2) cage at R5C5 = {24}, (only remaining combination), locked for N5 and D/
7o. 11(2) cage at R5C4 = [56]
7p. 17(5) cage at R3C5 = {12356} (only remaining combination) -> R3C56 = [26] -> R5C5 = 4, placed for D\, R6C6 = 2, R3C3 = 5, placed for D\, R5C89 = [83], R4C8 = 4, R9C9 = 1, placed for D\, R5C6 = 9, R4C5 = 3
7q. Naked pair {24} in R12C7, locked for C7 and N3 -> R1C8 = 5, R7C7 = 9, placed for D\, R7C3 = 8

8. 12(3) cage at R1C4 = {147} (only remaining combination) -> R1C5 = 7, R12C4 = {14}, locked for C4 and N2
8a. R12C6 = [35], R2C5 = 9
8b. R1C1 = 2, placed for D\
8c. R12C7 = [42], R12C4 = [14], R1C23 = [89], R4C123 = [896], R8C2 = 5, R78C9 = [54], R78C5 = [18], R8C67 = [27]
8d. Naked pair {13} in R28C3, locked for C3 -> R6C23 = [34]
8e. R2C2 = 6, placed for D\

and the rest is naked singles, without using the diagonals.

Rating Comment:
I'll rate my walkthrough at 1.5. I used some heavy permutation analysis for my first breakthrough, then several forcing chains.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 6 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group