SudokuSolver Forum

A forum for Sudoku enthusiasts to share puzzles, techniques and software
It is currently Thu Apr 25, 2024 6:53 am

View unanswered posts | View active topics


Board index » Puzzles and Solutions » Samurai

All times are UTC




Post new topic Reply to topic  Page 1 of 1
  [ 9 posts ] 
  Print view Previous topic | Next topic 
Author Message
tarek
 Post subject: Regular Samurai #32
PostPosted: Mon Dec 01, 2008 7:53 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Tue Aug 05, 2008 11:43 am
Posts: 251
Regular Samurai #32A (Apprentice)
Rating based on required solving techniques:  Hard / VERY HARD

Image
32A Line Format:
Code:
6.9.........3..417.4.8.........13..6356..........6.3.9...9.7...8.4........2..4...
....56.9.5.4.8..7.28.....3....7.9....93...........49.7...86..........3.2...3....9
............5.9......6.......6.1..........651..8.7.......2........1.3............
..3..5...1.9.........6.1.......1.5.6548..........87..4.6.9........8..9278.2......
...8....4......1.6...96.........72.3.35.........3.6...18.....3.4.2.9..7.....18.6.
Top
 Profile  
Reply with quote  
Børge
 Post subject: Re: Regular Samurai #32
PostPosted: Mon Dec 01, 2008 10:13 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Mon Apr 21, 2008 10:32 am
Posts: 868
How is the Hard / VERY HARD rating to be interpreted?
That the puzzle is easiest solved with ore or more X-Wings, which are not really required, i.e. that the puzzle can be solved with Intersections and N/H-Subsets only?

_________________
Quis custodiet ipsos custodes?
Normal: [D  Y-m-d,  G:i]     PM->email: [D, d M Y H:i:s]
Top
 Profile  
Reply with quote  
tarek
 Post subject: Re: Regular Samurai #32
PostPosted: Mon Dec 01, 2008 11:19 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Tue Aug 05, 2008 11:43 am
Posts: 251
Børge wrote:
How is the Hard / VERY HARD rating to be interpreted?
That the puzzle is easiest solved with ore or more X-Wings, which are not really required, i.e. that the puzzle can be solved with Intersections and N/H-Subsets only?
Without giving too much away, I'm pleased that my rating generated those thoughts.

I've seen a few comments by board members describing x-wings as HARD rather than VERY HARD, this is my opinion as well & will Unite ratings of all Apprentices at HARD.

tarek
Top
 Profile  
Reply with quote  
Børge
 Post subject: Re: Regular Samurai #32
PostPosted: Tue Dec 02, 2008 7:58 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Mon Apr 21, 2008 10:32 am
Posts: 868
tarek wrote:
I've seen a few comments by board members describing x-wings as HARD rather than VERY HARD, this is my opinion as well & will Unite ratings of all Apprentices at HARD.
I have absolutely no problems with that. In my rating table I have downgraded X-Wing from Very Hard to Hard (a sure sell recommendation ... SIC) and upgraded Grouped Fish from Extra Hard to Super Hard (a sure buy recommendation). As a wrote back in July I am open to suggestions for up- or down-grading techniques, and this is the first suggestion.

Here my adjusted rating table:
Code:
Rating               Techniques required
======               ===================

Very Easy            Naked Singles only.

Easy                 Naked and Hidden Singles only.

Moderate             Easier techniques + Intersections   aka.   Block/Block Interactions   aka.   Locked Candidates
                                       + Hidden Extra Groups + Twin Nonets

Tough                Easier techniques + Naked and/or Hidden Pairs.

Hard                 Easier techniques + Naked and/or Hidden Triplets/Quads + X-Wing.

Very Hard            Easier techniques + Swordfish, Jellyfish and/or Squirmbag.

Extra Hard           Easier techniques + Finned Fish + Colouring + Skyscraper + Two String Kite + Remote Pairs + Empty Rectangle.

Super Hard           Easier techniques + Grouped Fish + Wings + Uniqueness Test 1.

Ultra Hard           Easier techniques + Chains + Uniqueness Test 2 trough 6.

Nightmare            Easier techniques + any other techniques except Pure Guessing and Brute Force.

Hellish Nightmare    Easier techniques + Pure Guessing and Brute Force.

_________________
Quis custodiet ipsos custodes?
Normal: [D  Y-m-d,  G:i]     PM->email: [D, d M Y H:i:s]
Top
 Profile  
Reply with quote  
Børge
 Post subject: Re: Regular Samurai #32
PostPosted: Sun Dec 07, 2008 3:13 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Mon Apr 21, 2008 10:32 am
Posts: 868
Tarek, thanks for another fun Samurai.

Here a mini-mini Walktrough:
Hidden Text:
A couple of Intersections and N/H-Singles are required before:



Image



Directly followed by



Image



Directly followed by



Image

_________________
Quis custodiet ipsos custodes?
Normal: [D  Y-m-d,  G:i]     PM->email: [D, d M Y H:i:s]


Last edited by Børge on Sat Mar 21, 2009 4:07 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
tarek
 Post subject: Re: Regular Samurai #32
PostPosted: Sun Dec 07, 2008 5:09 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Tue Aug 05, 2008 11:43 am
Posts: 251
I'm glad that you enjoyed solving it. I confess to being slightly behind in solving puzzles.

I'm glad that you agreed on the downgrade of difficulty suggested.

Your solution BTW is one of possible paths to solution. The puzzle was designed to expose different solution paths because I know that people solve these puzzles differently. Oh, & there is the Red Herring !!?

tarek
Top
 Profile  
Reply with quote  
Børge
 Post subject: Re: Regular Samurai #32
PostPosted: Sun Dec 07, 2008 6:18 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Mon Apr 21, 2008 10:32 am
Posts: 868
tarek wrote:
Your solution BTW is one of possible paths to solution.
I know. I explored a couple of lengthier paths with more Intersections and N/H-Subsets before finding the one presented in the walkthrough.
Hidden Text:
After finding the X-Wing on 7 in g5 the solution path becomes much narrower and any further progress depends on finding the Naked Pair {25} in g3:r8c37


tarek wrote:
The puzzle was designed to expose different solution paths because I know that people solve these puzzles differently.
That's what I enjoy about your puzzles.

tarek wrote:
Oh, & there is the Red Herring !!?
:? Please give a hint! :bouncy:

_________________
Quis custodiet ipsos custodes?
Normal: [D  Y-m-d,  G:i]     PM->email: [D, d M Y H:i:s]
Top
 Profile  
Reply with quote  
tarek
 Post subject: Re: Regular Samurai #32
PostPosted: Sun Dec 07, 2008 8:22 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Tue Aug 05, 2008 11:43 am
Posts: 251
Børge wrote:
tarek wrote:
Oh, & there is the Red Herring !!?
:? Please give a hint! :bouncy:
Well,

if you consider that x-subsets (hidden or naked) are easier than (x+n)-subsets then your naked quint will be equivalent to a hidden double.

The red herring is a hidden triple in g1 which is not needed :scratch:

tarek
Top
 Profile  
Reply with quote  
Børge
 Post subject: Re: Regular Samurai #32
PostPosted: Sun Dec 07, 2008 9:02 pm 
Offline
Grand Master
Grand Master
User avatar

Joined: Mon Apr 21, 2008 10:32 am
Posts: 868
tarek wrote:
Well, if you consider that x-subsets (hidden or naked) are easier than (x+n)-subsets then your naked quint will be equivalent to a hidden double.
Seeing that the Naked Quintuplet has a complementary Hidden Pair {48}, was left as an exercise to the reader. Looking at the image I posted, the Hidden Pair actually jumps out grabs you.

Personally I find it much easier finding Naked Subsets, even large ones, than Hidden Subsets. And since every Hidden Subset must have one ore more complementary Naked Subset(s) .....

tarek wrote:
The red herring is a hidden triple in g1 which is not needed :scratch:
Ooops, had forgotten what the English idiom "Red Herring" means and momentarily thought that it was a "new" Sudoku term that I did not know. :bigoops: :lol: 8-)
In addition to the red herring Hidden Triplet, there are also 1 Naked Triplet and 2 Naked Quads red herrings.

_________________
Quis custodiet ipsos custodes?
Normal: [D  Y-m-d,  G:i]     PM->email: [D, d M Y H:i:s]
Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 1 of 1
  [ 9 posts ] 

Board index » Puzzles and Solutions » Samurai

All times are UTC


Who is online

Users browsing this forum: No registered users and 16 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