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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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 Posted: Mon Jan 14, 2008 8:14 am Post subject: extreme # 917 |
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| Code: | . 7 9 | 4 . . | 2 . .
. 3 . | . . . | . . .
5 2 . | . 7 3 | . 6 .
---------------------
4 . . | 3 . . | . . 9
. . . | . 8 . | . . .
2 . . | . . 9 | . . 5
---------------------
. 8 . | 9 3 . | . 4 1
. . . | . . . | . 8 .
. . 3 | . . 5 | 7 9 . |
http://www.sudoku.org.uk/DailySudoku.asp?day=13/01/2008
what happened to the los angeles times and the daily telegraph puzzles?? the daily telegraph website hasn't had one since the new year. |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Mon Jan 14, 2008 5:31 pm Post subject: |
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the long and winding road ...
after basics, there is an xy-wing (78-84-47 pivot r6c7) removes 7 from r5c3.
But then ...
| Code: |
+--------------------------+--------------------------+--------------------------+
| 168 7 9 | 4 56 68 | 2 15 3 |
| 168 3 16 | 256 9 268 | 14 157 47 |
| 5 2 4 | 1 7 3 | 9 6 8 |
+--------------------------+--------------------------+--------------------------+
| 4 56 78 | 3 25 17 | 168 127 9 |
| 3 9 56 | 25 8 147 | 146 127 47 |
| 2 1 78 | 67 46 9 | 48 3 5 |
+--------------------------+--------------------------+--------------------------+
| 7 8 26 | 9 3 26 | 5 4 1 |
| 9 456 1256 | 267 1246 47 | 3 8 26 |
| 16 46 3 | 8 1246 5 | 7 9 26 |
+--------------------------+--------------------------+--------------------------+
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From here, I needed 3 (three!) xy-chains and some more coloring (on 6) to solve the puzzle. There's got to be a better way!
___
LA times sudoku seems to be up http://games.latimes.com/index_sudoku.html?uc_feature_code=lasud&uc_full_date=20080111 but I remember having problems when I tried in December. |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Mon Jan 14, 2008 6:35 pm Post subject: |
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| Code: | *---------------------------------------------------*
|#168 7 9 | 4 56 #68 | 2 15 3 |
|#168 3 16 | 256 9 #268 | 14 157 47 |
| 5 2 4 | 1 7 3 | 9 6 8 |
|-----------------+-----------------+---------------|
| 4 56 78 | 3 25 17 | 168 127 9 |
| 3 9 56 | 25 8 147 | 146 127 47 |
| 2 1 78 | 67 46 9 | 48 3 5 |
|-----------------+-----------------+---------------|
| 7 8 2-6 | 9 3 @26 | 5 4 1 |
| 9 456 1256 | 267 1246 47 | 3 8 26 |
|@16 46 3 | 8 124-6 5 | 7 9 26 |
*---------------------------------------------------*
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UR 68: either (r12c1=1 => r9c1=6) or (r2c6=2 => r7c6=6).
=> r7c3<>6, r9c5<>6
But i had 2 xy-chains after that too (the longer one was enough to solve it). |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Mon Jan 14, 2008 6:50 pm Post subject: |
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| ok, I found the la times. friday's puzzle is tough |
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Johan
Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium
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| Posted: Mon Jan 14, 2008 7:24 pm Post subject: |
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After a naked [147] triple in C6 and a hidden [25] pair in Box 5, i found a 6-cell(ABCDEF) xy-chain, both pincer ends in R6C5(A) and R5C9(F) takes out <4>
in R5C6 and R6C7, which opens up an idle [26-56-25] xy-wing@, transporting the <2> from R7C3(R7C3=2 => R7C6=6 => R1C6=8 => R2C6=2 => R2C4=5 => R5C4=2) pins
<2> in R5C4, solving the puzzle.
| Code: |
+--------------------------+--------------------------+--------------------------+
| 168 7 9 | 4 B 56 68 | 2 C 15 3 |
| 168 3 16 | 256 9 268 | 14 D 157 E 47 |
| 5 2 4 | 1 7 3 | 9 6 8 |
+--------------------------+--------------------------+--------------------------+
| 4 56 5678 | 3 25 17 | 168 127 9 |
| 3 9 @567 |@25 8 1-[4]7 | 146 127 F 47 |
| 2 1 78 | 67 A 46 9 |-[4]8 3 5 |
+--------------------------+--------------------------+--------------------------+
| 7 8 @26 | 9 3 26 | 5 4 1 |
| 9 456 1256 | 267 1246 47 | 3 8 26 |
| 16 46 3 | 8 1246 5 | 7 9 26 |
+--------------------------+--------------------------+--------------------------+ |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Mon Jan 14, 2008 10:29 pm Post subject: |
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Ah, my chain to solve it had 8 cells (no 2 in r2c4 in my grid then - eliminated 5 in r1c5). But your 6-cell was there from the beginning.
Sorry to have pre-empted you with the UR, i am sure you (would have) spotted it  |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Tue Jan 15, 2008 1:39 am Post subject: |
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From nataraj's position after the {478} XY Wing:
(2) {256} XY Wing pivot r5c3 with r5c4 transported to r2c6 removes <2> from r7c6.
(3) {47} W-Wing removes <7> from r5c6.
(4) {125} XY Wing pivot r4c8 removes <5> from r1c5.
This solves the puzzle without any chains (if you don't count the transported pincer) or DPs. |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Tue Jan 15, 2008 7:38 am Post subject: |
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now that I did the puzzle again from my posted position above I realized that my first chain is almost the same as Asellus' first elimination - it starts with the same (useless) XY-wing, but transports both ends:
a) '26' (r7c6) - [xy wing 26-56-52] - '25' - '56'(r1c5) => r1c6=8
The second chain is short (just 4 cells, little more than a failed xy-wing with one leg added)
b) '14'(r2c7)-'15'(r1c8)-'56'(r1c5)-'46'(r6c5) => r6c7=8
No need for a third chain, only the coloring elimination in 6 I spoke of.
Asellus, I don't see how the w-wing (47) is connected (I assume the ends to be r5c9 and r8c6?) |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Tue Jan 15, 2008 11:28 am Post subject: |
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| nataraj wrote: | | Asellus, I don't see how the w-wing (47) is connected (I assume the ends to be r5c9 and r8c6?) |
Oops! It seems I had "crooked vision"! Somehow, I saw the <4> pair in b5 as lining up properly. 
I guess you need those chains after all. |
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