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 Post subject: Regular Samurai #16
PostPosted: Mon Aug 11, 2008 9:47 pm 
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Regular Samurai #16A (Apprentice)

Image
16A Line Format:
Code:
9..1......2...4.....7..3..6.1..97......3....2......83.239......7.........8.4.....
.6..9........4.87.2.9..........2..........36..3..8.2..8..9..1.....1.5.4...12..6..
...6..8......3............1.....8...6...9.....52..............7.............6.4..
.....9....7.......9...2....6..3..........8.....821.4...31...8.....7351....5......
..79..12......4..64....7......8..4..3.2...8.......259...8.5..3..9...8...........9


Regular Samurai #16B (Master)

Image
16B Line Format:
Code:
9......6...49....1...827..5.2.1..3....8...........2..9..2.1...3.9...........4.7..
..........7..6..3.6.514..2..8..........2.1.79159......5.....9.....4....6..2...1..
..3...5...........7.......2.....2...6...9..4.........6...1........8.........6....
...................527......8..2...9.4.5..1...3.1.4...8.52.......4....3......69..
....1.6.....4........2..........347......9...7...4...5..9...3..2.4..5.1..31.....9


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 Post subject: Re: Regular Samurai #16
PostPosted: Tue Aug 12, 2008 12:39 pm 
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I have just solved Regular Samurai #16A (Apprentice).
A nice and relaxing puzzle.
Perhaps a little bit too relaxing for my personal taste. 8-)

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 Post subject: Re: Regular Samurai #16
PostPosted: Tue Aug 12, 2008 3:40 pm 
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I have now also done Regular Samurai #16B (Master). A nice and challenging puzzle.

Here a mini-mini Walktrough:
Hidden Text:
The grids 2, 3, 4 and 5 solve with N/H-Singles, Intersections and N/H-Subsets.


Then the two final moves to crack grid 1:

X-Wing on 7 in R57C14 (green cells). Alternatively there is a Swordfish on 7 (yellow cells), which yields the exact same eliminations as the X-Wing.
Image


Y-Wing with strong link on 7 in Row 4, r5c4 + r6c8 = {57} => r6c4 <> 5
OR
XY-X-Chain with three links, starting in r7c8 and ending in r5c4
Image

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 Post subject: Re: Regular Samurai #16
PostPosted: Fri Aug 15, 2008 8:19 am 
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Spot on Børge.

I knew they were fun......

tarek


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 Post subject: Re: Regular Samurai #16
PostPosted: Sun Oct 24, 2010 11:05 pm 
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Well, crud! I got through almost all of the master-level puzzle but got stuck on grid #1 (everything else is solved). Sudocue is insisting that the grid can't be solved with the techniques I know (up to X-wing/Swordfish), and suggests a 2-string kite. I have no idea how to do those. Is this puzzle not solvable without this or another advanced move?


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 Post subject: Re: Regular Samurai #16
PostPosted: Mon Oct 25, 2010 9:21 pm 
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enxio27 wrote:
Is this puzzle not solvable without this or another advanced move?
Three posts above, I have posted a mini-mini Walktrough with images, which shows that either a "Y-Wing" or an "XY-X-Chain" is needed to solve grid #1.
The suggested "2-string kite" is a red herring and will get you nowhere!


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 Post subject: Re: Regular Samurai #16
PostPosted: Mon Oct 25, 2010 9:32 pm 
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Børge wrote:
Three posts above, I have posted a mini-mini Walktrough with images, which shows that either a "Y-Wing" or an "XY-X-Chain" is needed to solve grid #1.

Darn! I guess I'll have to put this one in my "wait until I learn more techniques" pile, then. It was all going so well, too, until I got to that point. I think Y-wing is coming up soon, though (working my way through Tom Davis' tutorial), so maybe I won't have to wait too long to finish this one.

Quote:
The suggested "2-string kite" is a red herring and will get you nowhere!

Oh, great! :brickwall: Thanks for the warning!


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 Post subject: Re: Regular Samurai #16
PostPosted: Mon Oct 25, 2010 9:43 pm 
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A hint:
  1. Check if you in R4 can only have the digit 7 in two cells.
  2. If YES, continue with step 3, otherwise you can solve further with techniques you know.
  3. Let's call the two cells in R4 with the digit 7 for R4C1 and R4C2.
  4. Look for a cell seen by R4C1 with only two possible digits, one of them being the digit 7.
  5. Look for a cell seen by R4C2 with only two possible digits, one of them being the digit 7.
  6. See if you now can eliminate a single digit from one or more cells.


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 Post subject: Re: Regular Samurai #16
PostPosted: Mon Oct 25, 2010 10:21 pm 
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Børge wrote:
A hint:
  1. Check if you in R4 can only have the digit 7 in two cells.
  2. If YES, continue with step 3, otherwise you can solve further with techniques you know.
  3. Let's call the two cells in R4 with the digit 7 for R4C1 and R4C2.
  4. Look for a cell seen by R4C1 with only two possible digits, one of them being the digit 7.
  5. Look for a cell seen by R4C2 with only two possible digits, one of them being the digit 7.


So far so good, but I'm evidently missing the logic. I have:

R4C5: 5 6 7
R4C8: 5 7
R8C5: 6 7
R6C8: 5 7

but I'm not seeing the elimination.


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 Post subject: Re: Regular Samurai #16
PostPosted: Mon Oct 25, 2010 10:39 pm 
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4.  Look for a cell seen by R4C5 with only two possible digits, one of them being the digit 7, and the other one the digit Z.
5.  Look for a cell seen by R4C8 with only two possible digits, one of them being the digit 7, and the other one the digit Z.
6.  See if you now can eliminate the digit Z from one or more cells.

The cells you are looking for:
R4C5:  5 6 7
R4C8:  5 7
R5C4:  5 7
R6C8:  5 7

Can you see the elimination(s) now?


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