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 

Puzzle NR_069

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Puzzles by daj
View previous topic :: View next topic  
Author Message
daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Fri Oct 16, 2009 2:32 am    Post subject: Puzzle NR_069 Reply with quote

Code:
NR puzzles can be solved using these techniques:

Basics:  Naked/Hidden Single, Naked Pair/Triple, Locked Candidates 1/2
Basics+: Naked Quad, Hidden Pair/Triple/Quad
VH:      BUG+1, UR Type 1, X-Wing, XY-Wing
VH+:     2-String Kite, Empty Rectangle, Remote Pair, Skyscraper,
         XYZ-Wing, finned X-Wing, UR Type 2/4

Code:
 +-----------------------+
 | . . . | 9 6 . | . 4 2 |
 | . . . | . . 3 | 1 5 . |
 | . . . | 4 5 . | . . . |
 |-------+-------+-------|
 | 1 . 9 | . . 6 | 4 . 5 |
 | 3 . 4 | . 9 . | . 6 . |
 | . 6 . | 2 . . | . . . |
 |-------+-------+-------|
 | . 1 . | 6 . . | . . 8 |
 | 4 5 . | . 8 . | . 3 . |
 | 6 . . | 5 . . | 2 . . |
 +-----------------------+

Play this puzzle online at the Daily Sudoku site
Back to top
View user's profile Send private message
storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Fri Oct 16, 2009 5:24 pm    Post subject: Reply with quote

not to give too much away, but this puzzle is solved with 5 VH steps, I think.

BUT.

here is another route.

this is after basics...
Code:
.---------------------.---------------------.---------------------.
| 578    37     1357  | 9      6      178   | 378    4      2     |
| 789    4      67    | 78     2      3     | 1      5      679   |
| 2789   379    12367 | 4      5      178   | 36789  789    3679  |
:---------------------+---------------------+---------------------:
| 1      8      9     | 3      7      6     | 4      2      5     |
| 3      2      4     | 18     9      5     | 78     6      17    |
| 57     6      57    | 2      14     48    | 389    189    139   |
:---------------------+---------------------+---------------------:
| 279    1      237   | 6      34     2479  | 5      79     8     |
| 4      5      27    | 17     8      279   | 679    3      1679  |
| 6      379    8     | 5      13     79    | 2      179    4     |
'---------------------'---------------------'---------------------'



(7=3)r1c2 - (3)r9c1 = (3)r9c5 - (3=4)r7c5 - (4=1)r6c5 - (1=8)r5c4 - (8=7)r2c4
r1c6, r2c13 are all not 7


ALS[(9)r7c1 = (3)r7c3]r78c13 - (3)r7c5 = (3-1)r9c5 = (1)r6c5 - (1=8)r5c4 - (8=7)r2c4 - (7=9)r2c9
r2c1 is not 9

bunch of singles
naked pair
intersection in there.


xy-wing finishes.
removes 9 from r8c9
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Fri Oct 16, 2009 6:39 pm    Post subject: Reply with quote

storm_norm wrote:
not to give too much away, but this puzzle is solved with 5 VH steps, I think.

Two VH+ steps, but there are three VH steps (and another VH+ step) that I know also exist.
Back to top
View user's profile Send private message
arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Fri Oct 16, 2009 8:41 pm    Post subject: Reply with quote

Best I could do was an nice loop and xy-wing
Code:
 *--------------------------------------------------------------------*
 | 578    37     1357   | 9      6      178    | 378    4      2      |
 | 789    4      67     | 78     2      3      | 1      5      679    |
 | 2789   379    12367  | 4      5      178    | 36789  789    3679   |
 |----------------------+----------------------+----------------------|
 | 1      8      9      | 3      7      6      | 4      2      5      |
 | 3      2      4      | 18     9      5      | 78     6      17     |
 | 57     6      57     | 2      14     48     | 389    189    139    |
 |----------------------+----------------------+----------------------|
 | 279    1      237    | 6      34     2479   | 5      79     8      |
 | 4      5      27     | 17     8      279    | 679    3      1679   |
 | 6      379    8      | 5      13     79     | 2      179    4      |
 *--------------------------------------------------------------------*
 (7=8)r2c-(8)r5c4=(8-4)r6c6=(4-2)r7c6=(2)r8c6-(2=7)r8c3 => r2c3,r8c4<>7

 *--------------------------------------------------*
 | 57   37   157  | 9    6    18   | 38   4    2    |
 | 8    4    6    | 7    2    3    | 1    5    9    |
 | 29   39   12   | 4    5    18   | 368  78   67   |
 |----------------+----------------+----------------|
 | 1    8    9    | 3    7    6    | 4    2    5    |
 | 3    2    4    | 8    9    5    | 7    6    1    |
 | 57   6    57   | 2    1    4    | 89   89   3    |
 |----------------+----------------+----------------|
 |*29   1    3    | 6    4    279  | 5   *79   8    |
 | 4    5   *27   | 1    8    279  | 69   3    6-7  |
 | 6    79   8    | 5    3    79   | 2    1    4    |
 *--------------------------------------------------*
xy-wing 297
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Sat Oct 17, 2009 5:02 am    Post subject: Reply with quote

I used an XY(187), W (79) and XYZ (279).
Back to top
View user's profile Send private message
tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Tue Oct 20, 2009 4:32 pm    Post subject: Reply with quote

I initially spotted a xyz-wing 279 while looking for something else. This opened a xy-wing 23-7 with vertex 23 in r7c3, pincer 27 in r8c3 and an extended pincer on 7 ending in cell r2c4 to complete the puzzle.

Ted
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Puzzles by daj 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