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tarek
 Post subject: Regular Samurai #18
PostPosted: Mon Aug 25, 2008 1:10 am 
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Regular Samurai #18A (Apprentice)
Rating based on required solving techniques:  Very Hard

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18A Line Format:
Code:
...5.4...2.6...........9..847...........6.4......7.2...6..........7.8...18.......
....3.5..9.5.8.....3.....7.4..7.3.........89.7.6....3....2..6..........2...4.5...
....7.......................6..........1..5......5.8.2.........8....2......9.8...
..........2....8.....18.....8....1.....953....5......23......9....6.7.....9....15
...2..7.9....4.......9....8.9....5...2..73.........6.4...7.1.5.8.1....4...9..6...
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Børge
 Post subject: Re: Regular Samurai #18
PostPosted: Mon Aug 25, 2008 12:25 pm 
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tarek, thanks for an excellent Apprentice level puzzle :cheers: :applause:
Definitely more challenging than #16A.

Here a mini-mini Walktrough:
Hidden Text:
The only grid that solves completely with N/H-Singles, Intersections and N/H-Subsets only, before the cracking X-Wing, is grid 2.


X-Wing on 3 in g5:r28c47 (green cells). The grids 1, 3, 4 and 5 then solve with N/H-Singles and Intersections.
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Last edited by Børge on Sat Mar 21, 2009 3:42 pm, edited 1 time in total.

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tarek
 Post subject: Re: Regular Samurai #18
PostPosted: Tue Aug 26, 2008 3:25 pm 
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I'm glad you found the correct x-wing :applause:

tarek
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Børge
 Post subject: Re: Regular Samurai #18
PostPosted: Wed Aug 27, 2008 1:25 pm 
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tarek wrote:
I'm glad you found the correct x-wing :applause:
Luckily, first during the analysis walktrough I detected the second one (you put in as a diversion), which gets you no real advancement.
Detecting the right X-Wing early also saves you at least one Naked Quad (or a Hidden Pair). According to JSudoku finding that X-Wing early enough saves you all N/H-Subsets!
Hidden Text:
X-Wing on 3 in g5:r28c47 (green cells) => eliminations in pink cells. Naked Quad 1236 in orange cells [or Hidden pair 59 in g5:r68c5 ].

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