dailysudoku.com Forum Index dailysudoku.com
Discussion of Daily Sudoku puzzles
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

June 27, VH

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Daily Sudoku puzzles
View previous topic :: View next topic  
Author Message
prakash



Joined: 02 Jan 2008
Posts: 67
Location: New Jersey, USA

PostPosted: Fri Jun 27, 2008 12:55 am    Post subject: June 27, VH Reply with quote

I am sure I missed something simple. I had to jump through hoops to get his done. 2 XYZ wings, 1 X Wing and 1 XY Wing. Anybody spot something simpler?

XYZ Wing 13-143-43 removes 3 from R3C7
X Wing on 3 removes 3 from R2C5
XYZ Wing 49-479-79 removes 9 from R3C7
XY Wing 17-27-12 removes 1 from R1C5
Back to top
View user's profile Send private message
wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.

PostPosted: Fri Jun 27, 2008 4:40 am    Post subject: Re: June 27, VH Reply with quote

prakash wrote:
Anybody spot something simpler?


Shorter, yep. I find 2 string kites to be horribly hard to spot.

Code:
Simple stuff to here where a two string kite eliminates the 4 in r3c6.
.---------------------.---------------------.---------------------.
| 17     4      3     | 89     18     5     | 6      79     2     |
| 12     5      9     | 46     12346  7     | 134    8      13    |
| 6      27     8     | 49     1234  #12-4  | 1349  @479    5     |
:---------------------+---------------------+---------------------:
| 5      9      2     | 1      7     *48    |*34     6      38    |
| 478    678    46    | 2      5      3     | 149   @49     18    |
| 48     3      1     | 468    468    9     | 5      2      7     |
:---------------------+---------------------+---------------------:
| 248    268    46    | 5      12     126   | 7      3      9     |
| 9      1      7     | 3      48     468   | 2      5      46    |
| 3      26     5     | 7      9      246   | 8      1      46    |
'---------------------'---------------------'---------------------'



That sets up an xy wing that sets r1c5 to 8.  The rest is simple.

.---------------------.---------------------.---------------------.
|*17     4      3     | 89    #8-1    5     | 6      79     2     |
| 12     5      9     | 46     12346  7     | 134    8      13    |
| 6     *27     8     | 49     1234  *12    | 1349   479    5     |
:---------------------+---------------------+---------------------:
| 5      9      2     | 1      7      48    | 34     6      38    |
| 478    678    46    | 2      5      3     | 149    49     18    |
| 48     3      1     | 468    468    9     | 5      2      7     |
:---------------------+---------------------+---------------------:
| 248    268    46    | 5      12     126   | 7      3      9     |
| 9      1      7     | 3      48     468   | 2      5      46    |
| 3      26     5     | 7      9      246   | 8      1      46    |
'---------------------'---------------------'---------------------'
Back to top
View user's profile Send private message
Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Fri Jun 27, 2008 4:41 am    Post subject: Reply with quote

W-Wing, Type 4 UR, W-Wing. The UR probably wasn't needed.
Back to top
View user's profile Send private message
wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.

PostPosted: Fri Jun 27, 2008 4:54 am    Post subject: Reply with quote

I so like it that different paths are often easy to find.

Sudoku would be stale if there was only one path and order. Sad

I confirm that the UR is not needed.
Back to top
View user's profile Send private message
storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Fri Jun 27, 2008 5:30 am    Post subject: Reply with quote

Code:
.---------------------.---------------------.---------------------.
|*17     4      3     | 89    *18     5     | 6      79     2     |
|#12     5      9     | 46    1-2346  7     | 134    8      13    |
| 6      27     8     | 49     1234   124   | 1349   479    5     |
:---------------------+---------------------+---------------------:
| 5      9      2     | 1      7      48    | 34     6      38    |
| 478    678    46    | 2      5      3     | 149    49     18    |
| 48     3      1     | 468    468    9     | 5      2      7     |
:---------------------+---------------------+---------------------:
| 248    268    46    | 5     #12     126   | 7      3      9     |
| 9      1      7     | 3      48     468   | 2      5      46    |
| 3      26     5     | 7      9      246   | 8      1      46    |
'---------------------'---------------------'---------------------'


w-wing {1,2} through the ones in the first row, removes 2 in r2c5

(2=1)r2c1-(1)r1c1=(1)r5c1-(1=2)r7c5; r2c5<>2
Back to top
View user's profile Send private message
nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Fri Jun 27, 2008 5:55 am    Post subject: Reply with quote

Something simple?

An xyz-wing very early on: 4,7,9 in row 3 + box 3, removes 9 from r3c7. From there, basic stuff for a while.

Near the end, either a UR (26 r79c26 with strong link 6 in r7) or an xy-wing pivot r3c2 (17-27-12)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Johan



Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium

PostPosted: Fri Jun 27, 2008 8:59 am    Post subject: Reply with quote

I used the strong link* on <2> in C1, which eliminates <1> in R1C5 collapsing the whole puzzle. Either R2C1=2 or R7C1=2.

R2C1=2 => R1C1=1(a)

R7C1=2 => R7C5=1(b)
Code:
+-------------------------+-------------------------+-------------------------+
| 17 a      4         3   | 89      -[1]8      5    | 6         79        2   |
|*12        5         9   | 46        12346    7    | 134       8         13  |
| 6         27        8   | 49        1234     124  | 1349      479       5   |
+-------------------------+-------------------------+-------------------------+
| 5         9         2   | 1         7        48   | 34        6         38  |
| 478       678       46  | 2         5        3    | 149       49        18  |
| 48        3         1   | 468       468      9    | 5         2         7   |
+-------------------------+-------------------------+-------------------------+
|*248       268       46  | 5         12 b     126  | 7         3         9   |
| 9         1         7   | 3         48       468  | 2         5         46  |
| 3         26        5   | 7         9        246  | 8         1         46  |
+-------------------------+-------------------------+-------------------------+
Back to top
View user's profile Send private message Send e-mail
cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Fri Jun 27, 2008 2:34 pm    Post subject: Reply with quote

Remarkably easy really. I simply used the following:

x-wing on <6>
xyz-wing on <134>
x-wing on <2>
ER on <4>
xy-wing on <127>

A three coffee job at most. Twisted Evil
Back to top
View user's profile Send private message
Earl



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS

PostPosted: Fri Jun 27, 2008 4:31 pm    Post subject: VH Reply with quote

An xyz-wing (479), then an xy-wing (127) (all in boxes 1-2-3) did it for me.

Earl
Back to top
View user's profile Send private message Send e-mail
Clement



Joined: 24 Apr 2006
Posts: 1111
Location: Dar es Salaam Tanzania

PostPosted: Sat Jun 28, 2008 5:25 pm    Post subject: Daily Sudoku: Fri 27-Jun-2008 VH Reply with quote

I used the BUG Principle.Candidate 9 is the only one that appears three times in c8.Therefore, 9 must go in r3c8 which is the only three candidate cell in the column. That solves the puzzle.
Back to top
View user's profile Send private message AIM Address
nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Sat Jun 28, 2008 6:02 pm    Post subject: Re: Daily Sudoku: Fri 27-Jun-2008 VH Reply with quote

Clement wrote:
I used the BUG Principle.Candidate 9 is the only one that appears three times in c8.Therefore, 9 must go in r3c8 which is the only three candidate cell in the column. That solves the puzzle.


"Careful with that axe, Eugene ..."

Clement, could you explain that a bit more? I do not have my grid available any more but I do remember that all essential steps in solving the puzzle occured at a time when I was still FAR AWAY from a "BUG" situation. The BUG+1 or BUG+n reasoning only comes into play, when almost all cells in the puzzle are either solved or have only two candidates left.

Looking at the posted grids here, I see a lot of three- four- and even five-candidate cells at the critical points.

Maybe you run that grid with the BUG+1 by us and also how you got there?
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Daily Sudoku puzzles All times are GMT
Page 1 of 1

 
Jump to:  
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 vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group