SudokuSolver Forum

A forum for Sudoku enthusiasts to share puzzles, techniques and software
It is currently Tue Mar 19, 2024 6:06 am

All times are UTC




Post new topic Reply to topic  [ 15 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Christmas Killer 2017
PostPosted: Sun Dec 24, 2017 2:48 pm 
Offline
Grand Master
Grand Master

Joined: Wed Apr 30, 2008 9:45 pm
Posts: 692
Location: Saudi Arabia
Christmas Killer 2017

Not quite an assassin SS gives it 1.1, but pleasant anyway.

Image

JS Code:

3x3::k:15:4360:16:17:5644:5644:5644:5129:18:4360:4360:4360:19:4359:20:5129:5129:5129:21:4360:22:4359:4359:4359:23:5129:24:25:8203:2574:2574:4359:2573:2573:8458:26:8203:8203:8203:2566:2566:2566:8458:8458:8458:27:8203:4357:4357:4357:4357:4357:8458:28:29:7684:7684:7684:7684:7684:7684:7684:30:4354:4354:4354:4354:4354:7171:7171:7171:7171:31:32:33:2305:2305:2305:34:35:36:


Last edited by HATMAN on Thu Dec 28, 2017 2:36 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
PostPosted: Mon Dec 25, 2017 5:35 am 
Offline
Grand Master
Grand Master

Joined: Wed Apr 23, 2008 6:04 pm
Posts: 1893
Location: Lethbridge, Alberta, Canada
Thanks HATMAN for a fun Christmas Killer. :santa:

Here is my walkthrough:
Prelims

a) R4C34 = {19/28/37/46}, no 5
b) R4C67 = {19/28/37/46}, no 5
c) 22(3) cage at R1C5 = {589/679}
d) 10(3) cage at R5C4 = {127/136/145/235}, no 8,9
e) 9(3) cage at R9C4 = {126/135/234}, no 7,8,9
f) 28(4) cage at R8C6 = {4789/5689}, no 1,2,3
g) 17(5) cage at R1C2= {12347/12356}, no 8,9
h) 17(5) cage at R2C5= {12347/12356}, no 8,9
i) 32(5) cage at R4C2 = {26789/35789/45689}, no 1
j) 33(5) cage at R4C8 = {36789/45789}, no 1,2
k) 17(5) cage at R6C3 = {12347/12356}, no 8,9
l) 17(5) cage at R8C1= {12347/12356}, no 8,9

Steps resulting from Prelims
1a. 22(3) cage at R1C5 = {589/679}, 9 locked for R1
1b. 17(5) cage at R1C2= {12347/12356}, 1,2,3 locked for N1
1c. 32(5) cage at R4C2 = {26789/35789/45689}, 8,9 locked for N4, clean-up: no 1,2 in R4C4
1d. 33(5) cage at R4C8 = {36789/45789}, 7,8,9 locked for N6, clean-up: no 1,2,3 in R4C6
1e. 17(5) cage at R6C3 = {12347/12356}, 1,2,3 locked for R6
1f. 9 in N1 only in R3C13, locked for R3
1g. 1 in R5 only in 10(3) cage at R5C4, locked for N5

2a. R4C46 = {89} (hidden pair in N5), locked for R4
2b. R4C46 = {89} -> R4C37 = {12}, locked for R4
2c. 17(5) cage at R2C5 = {12347/12356}, 1,2 locked for N2
2d. R6C28 = {89} (hidden pair in R6)
2e. 45 rule on R6 2 remaining innies R6C19 = 11 = [56/65/74]
2f. 45 rule on R7 2 innies R7C19 = 15 = {69/78}
2g. R46C7 = {12} (hidden pair in N6), locked for C7
2h. 45 rule on N6 2 remaining innies R46C9 = 9 = [36/45/54]

3. 45 rule on N4 4 innies R46C13 = 13 = {1237/1246/1345}, 1 locked for C3
3a. 5,6,7 of {1237/1246/1345} must be in R6C1 -> no 5,6,7 in R4C1 + R6C3

4. 45 rule on R5 4 outies R46C28 = 30, R6C28 = {89} = 17 -> R4C28 = 13 = {67}, locked for R4

5. Hidden killer pair 8,9 in 30(7) cage at R7C2 and R8C6 for N8, 30(7) cage only contains one of 8,9 which must be in R7C456 -> R8C6 = {89}, no 8,9 in R7C2378
5a. Naked pair {89} in R48C6, locked for C6
5b. R17C5 = {89} (hidden pair in C5)
5c. Naked pair {89} in R7C5 + R8C6, locked for N8
[With hindsight it would have been better if I’d spotted step 5b first, then step 5 would have simplified to R7C5 + R8C6 = {89} (hidden pair for N8)]

6. Hidden killer pair 1,2 in R7C8 and R9C89 for N9, R9C89 cannot be {12} which would clash with 9(3) cage at R9C4 -> R7C8 = {12}, R9C89 must contain one of 1,2
6a. 9(3) cage at R9C4 = {135/234} (cannot be {126} which clashes with R9C89), 3 locked for R9 and N8
6b. Killer pair 1,2 in 9(3) cage and R9C89, locked for R9
6c. R7C7 = 3 (hidden single in N9)

7. 45 rule on N5 using R4C46 = {89} 1 remaining innie R4C5 = 2 outies R6C37 + 1
7a. Min R6C37 = {12} = 3 -> min R4C5 = 4
7b. R4C5 = {45} -> R6C37 = 3,4 = {12/13}, no 4
7c. 17(5) cage at R2C5= {12347/12356}, 3 locked for N2
7d. 4,5 of {12347/12356} must be in R4C5 -> no 4,5 in R2C5 + R3C456
7e. 10(3) cage at R5C4 contains 1 (step 1g) = {127/136} (cannot be {145} which clashes with R4C5), no 4,5
7f. Hidden killer pair 4,5 in 32(5) cage at R4C2 and 33(5) cage at R4C8 for R5, 33(5) cage contains both or neither of 4,5 -> 32(5) cage must contain both or neither of 4,5 = {26789/45689}, no 3, 6 locked for N4, clean-up: no 5 in R6C9 (step 2e), no 4 in R4C9 (step 2h)

8. R1C289 = {123} (hidden triple in R1)
8a. 45 rule on N3 4 innies R13C79 = 25, R1C9 = {123} -> R13C79 = {1789/2689/3589/3679}, no 4 -> R1C7 = 9, 1,2,3 of the combinations must be in R1C9 -> no 1,2,3 in R3C9 -> R3C79 = {5678}
8b. R1C7 = 9 -> R1C5 = 8, R1C6 = 5 (cage sum), R7C5 = 9, R8C6 = 8, R4C6 = 9 -> R4C7 = 1, R4C34 = [28], R6C3 = 1 (hidden single in N4)
8c. R46C13 (step 3) = {1237} (only remaining combination) -> R46C1 = [37], R4C28 = [67], R6C9 = 4 (step 2e), R4C59 = [45]
8d. 10(3) cage at R5C4 = {127} (hidden triple in R5), locked for N5
8e. R2C4 = 9 (hidden single in R2)
8f. R7C19 (step 2f) = [87] (only remaining permutation)
8g. 28(4) cage at R8C6 = {5689} (only remaining combination), 5,6,9 locked for R8 and N9
8h. 4 in N9 only in R9C78, locked for R9
8i. 9(3) cage at R9C4 = {135} (only remaining combination), locked for R9 and N8
8j. R7C8 = 1 (hidden single in N9)
8k. R9C123 = {679} (hidden triple in R9), locked for N7

9. 45 rule on N1 4 innies R13C13 = 28 = {4789/5689}
9a. 4,6 of {4789/5689} must be in R1C1 -> no 4,6 in R1C3 + R3C13 -> R1C3 = 7
9b. R13C13 = {4789} (only remaining combination) -> R1C1 = 4, R3C13 = [98]
9c. R1C7 + R3C9 = [96] -> R13C79 (step 8a) = {3679} (only remaining combination) ->R1C9 = 3, R3C7 = 7
9d. R2C56 = [74] (hidden pair in N2)

and the rest is naked singles.
Following up on the discussions in this thread about how to solve this puzzle, I've made one correction and added several clarifications to my steps.

Rating Comment:
I'll rate my walkthrough at 1.0; I used hidden triples and hidden killer pairs.

Solution:
4 1 7 6 8 5 9 2 3
2 3 6 9 7 4 8 5 1
9 5 8 1 3 2 7 4 6
3 6 2 8 4 9 1 7 5
5 9 4 2 1 7 6 3 8
7 8 1 5 6 3 2 9 4
8 2 5 4 9 6 3 1 7
1 4 3 7 2 8 5 6 9
6 7 9 3 5 1 4 8 2


Top
 Profile  
Reply with quote  
PostPosted: Mon Dec 25, 2017 4:37 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Thu Apr 24, 2008 4:27 pm
Posts: 791
1.1 on SS? I should be able to handle that. I will give it a try.

Here's the Sumocue for anyone who wants it (let me know if I made any mistakes):

Hidden Text:
Code:
3x3::k:0000:4352:0000:0000:5633:5633:5633:5122:0000:4352:4352:4352:0000:4355:0000:5122:5122:5122:0000:4352:0000:4355:4355:4355:0000:5122:0000:0000:8199:2566:2566:4355:2564:2564:8453:0000:8199:8199:8199:2568:2568:2568:8453:8453:8453:0000:8199:4361:4361:4361:4361:4361:8453:0000:0000:7690:7690:7690:7690:7690:7690:7690:0000:4363:4363:4363:4363:4363:7180:7180:7180:7180:0000:0000:0000:2317:2317:2317:0000:0000:0000:


Top
 Profile  
Reply with quote  
PostPosted: Fri May 25, 2018 2:00 am 
Offline
Grand Master
Grand Master
User avatar

Joined: Thu Apr 24, 2008 4:27 pm
Posts: 791
I've started this puzzle again (for the third time). The first time, I misplaced it. The second time, I got part way through it, then got busy and set it aside. I'm trying again, but I will have to review killer-specific techniques.


Top
 Profile  
Reply with quote  
PostPosted: Mon May 28, 2018 5:39 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Thu Apr 24, 2008 4:27 pm
Posts: 791
I'm having a tough time of it with this puzzle. :brickwall: Below is as far as I've gotten. Needless to say, I don't do many killers, but hopefully I haven't missed anything too simple or obvious. I understand the principle of innies and outies, but not sure how to apply them here (or even IF they can be applied here). I would prefer receiving instruction on applicable techniques rather than specific hints.

Code:
.-------------------------------.-------------------------------.-------------------------------.
| 45678     1234567   45678     | 12345678  89        56789     | 56789     12345678  12345678  |
| 1234567   1234567   234567    | 123456789 1234567   123456789 | 3456789   123456789 123456789 |
| 456789    1234567   456789    | 1234567   1234567   1234567   | 345678    12345678  12345678  |
:-------------------------------+-------------------------------+-------------------------------:
| 34567     34567     12        | 89        34567     89        | 12        34567     3456      |
| 23456789  23456789  23456789  | 1234567   1234567   1234567   | 3456789   3456789   3456789   |
| 4567      89        1234567   | 234567    234567    234567    | 12        89        456       |
:-------------------------------+-------------------------------+-------------------------------:
| 6789      123456789 23456789  | 123456789 89        123456789 | 3456789   123456789 6789      |
| 1234567   1234567   234567    | 1234567   1234567   456789    | 456789    456789    456789    |
| 123456789 123456789 23456789  | 123456    123456    123456    | 3456789   123456789 123456789 |
'-------------------------------.-------------------------------.-------------------------------'


Top
 Profile  
Reply with quote  
PostPosted: Tue May 29, 2018 7:04 am 
Offline
Grand Master
Grand Master

Joined: Wed Apr 16, 2008 1:16 am
Posts: 1039
Location: Sydney, Australia
enxio27 wrote:
I would prefer receiving instruction on applicable techniques rather than specific hints.
Unfortunately, most of the everyday techniques we use here don't have nice explanations in separate posts (we have done that for some of the more advanced techniques). We write walk-throughs (WT) and hope others can learn through understanding them.

Anyway, I can see a killer pair at that spot.

Also, Andrews WT at your spot does find some other things
implied cages (step 2f and 4)
4 cell hidden cage clean-up (step 3)
combination block -> hidden killer pair (step 6) (this looks like the key step for this puzzle)

If you want to go through Andrew's WT but can't understand something, please post!

Good on you for giving this one a go. 1.10 is quite a high score for someone who hasn't done many killers.

Do you use Sumocue? Why not SudokuSolver?

Cheers
Ed


Top
 Profile  
Reply with quote  
PostPosted: Wed May 30, 2018 1:23 am 
Offline
Grand Master
Grand Master
User avatar

Joined: Thu Apr 24, 2008 4:27 pm
Posts: 791
Ed wrote:
Unfortunately, most of the everyday techniques we use here don't have nice explanations in separate posts (we have done that for some of the more advanced techniques). We write walk-throughs (WT) and hope others can learn through understanding them.

Ed, thanks for getting back to me on this. I'm familiar with the techniques that apply to plain vanilla Sudoku, but I'm still trying to get a handle on the killer-specific ones. I've been avoiding walk-throughs (as well as hints from SudokuSolver) in an attempt to understand the logic behind the techniques instead of just being given the answers. Maybe I do need to go through a few killer walk-throughs, though, in order to grasp the techniques.

Quote:
Anyway, I can see a killer pair at that spot.

I'm still having difficulty understanding just what a killer pair is. Would you please explain?

Quote:
Also, Andrews WT at your spot does find some other things
implied cages (step 2f and 4)
4 cell hidden cage clean-up (step 3)
combination block -> hidden killer pair (step 6) (this looks like the key step for this puzzle)

If you want to go through Andrew's WT but can't understand something, please post!

I guess I will resign myself to checking the WT each time I get stuck on this puzzle.

Quote:
Good on you for giving this one a go. 1.10 is quite a high score for someone who hasn't done many killers.

I am apparently misunderstanding SS scores. I had thought that 1.10 was a pretty easy score. Evidently not.

Quote:
Do you use Sumocue? Why not SudokuSolver?

I do have the puzzle set up in SudokuSolver (using the Sumocue code) and have solved this puzzle to the point you see above. However, I was trying to avoid getting hints, as giving me the answers doesn't really help me see the logic behind the techniques.


Top
 Profile  
Reply with quote  
PostPosted: Wed May 30, 2018 8:16 am 
Offline
Grand Master
Grand Master

Joined: Wed Apr 16, 2008 1:16 am
Posts: 1039
Location: Sydney, Australia
Here's one explanation of killer pairs http://sudopedia.enjoysudoku.com/Killer_Subset.html

I think generally the newspaper killers get a score of .80 or .85. What we used to give a rating of 0.75 (ie, too easy for here, but harder than newspaper ones) is a score of .90 or .95. A score of 1.00 is around what Ruud did after the early ones. See here to get a sense viewtopic.php?p=706#p706

As you can see, the SS scores at the lower end don't match with the human ratings. This is because the algorithm is set at a high start since we (Richard and me) were trying to rate Assassins, not newspaper puzzles.

BTW - you can JSudoku code which HATMAN put at the base of the puzzle pic in the first post. That works for SS.

If you want to use SS for hints, I strongly recommend you go to the Solver menu, then Options, then Scoring radio button then Save radio button. That way you will get hints that match with the actual SSscores. The default settings are arranged according to some other criteria I never asked Richard about. They can be quite bizzare for killers: way too complicated. Also, his terminology is not standard and can be confusing.

You are correct, that SS and our WTs don't give the underlying logic many times.

I think Andrew's sticky, Advice for Newbies has some suggestions of puzzles to try first and some links to killer lingo, technique sites etc. viewtopic.php?f=3&t=466

As I said, please post if you can't understand Andrew's WT.

Cheers
Ed


Top
 Profile  
Reply with quote  
PostPosted: Wed May 30, 2018 11:13 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Thu Apr 24, 2008 4:27 pm
Posts: 791
Ed wrote:
Here's one explanation of killer pairs http://sudopedia.enjoysudoku.com/Killer_Subset.html

Thanks! Between this and Andrew's explanation to me in email, I think I understand now. I'll have to practice spotting them, though.

Quote:
I think generally the newspaper killers get a score of .80 or .85. What we used to give a rating of 0.75 (ie, too easy for here, but harder than newspaper ones) is a score of .90 or .95. A score of 1.00 is around what Ruud did after the early ones. See here to get a sense viewtopic.php?p=706#p706

Yep, I definitely misunderstood the ratings for killers. I probably wouldn't have touched this one if I had understood the ratings correctly. I probably should start with newspaper-grade killers instead.

Quote:
BTW - you can JSudoku code which HATMAN put at the base of the puzzle pic in the first post. That works for SS.

Yes, HATMAN added that to his post after I posted the Sumocue code I had exported from either JSudoku or SudokuSolver (I forget now which one).

Quote:
If you want to use SS for hints, I strongly recommend you go to the Solver menu, then Options, then Scoring radio button then Save radio button. That way you will get hints that match with the actual SSscores.

I will try that, thanks!

Quote:
I think Andrew's sticky, Advice for Newbies has some suggestions of puzzles to try first and some links to killer lingo, technique sites etc.

I did go through that sticky and the links that were mentioned, but was still having trouble. I'll have to look again for suggestions of puzzles that are more my speed.

Quote:
As I said, please post if you can't understand Andrew's WT.

Will do, thanks!


Top
 Profile  
Reply with quote  
PostPosted: Fri Jun 01, 2018 2:49 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Thu Apr 24, 2008 4:27 pm
Posts: 791
Going through Andrew's WT. I guess I'm not going to be able to solve this puzzle by myself.

Quote:
2c. 17(5) cage at R1C2 = {12347/12356}, 1,2 locked for N2
Should that be N1, or am I misunderstanding something?

Quote:
3a. R6C1 = {567} -> no 5,6,7 in R4C1 + R6C3
I have no clue how you are getting this. Please explain the logic.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 15 posts ]  Go to page 1, 2  Next

All times are UTC


Who is online

Users browsing this forum: No registered users and 4 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