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 

March 9 - hard

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



Joined: 19 Sep 2005
Posts: 3331
Location: near Detroit, Michigan, USA

PostPosted: Sun Mar 09, 2008 5:20 pm    Post subject: March 9 - hard Reply with quote

Try this one without pencil marks.

Hint: Placing the <6> in B2 breaks it wide open.

Keith
Back to top
View user's profile Send private message
Mindwarp



Joined: 13 Sep 2007
Posts: 25
Location: St. Ives, England

PostPosted: Sun Mar 09, 2008 6:06 pm    Post subject: Reply with quote

Hard, I don't think so doing it online took 4:08. That was one of the easiest hard puzzles I've done on here. There was absolutely nothing to it, just sweep and go!
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Sun Mar 09, 2008 6:39 pm    Post subject: Reply with quote

Mindwarp wrote:
Hard, I don't think so doing it online took 4:08. That was one of the easiest hard puzzles I've done on here. There was absolutely nothing to it, just sweep and go!

Hi Mindwarp,

Keith wasn't saying that this puzzle is hard to do, I think he's saying that it's interesting--possibly challenging--(I haven't done it) when doing it without pencil marks, i.e., no "Sweep."

Cheers.
Back to top
View user's profile Send private message
keith



Joined: 19 Sep 2005
Posts: 3331
Location: near Detroit, Michigan, USA

PostPosted: Sun Mar 09, 2008 7:27 pm    Post subject: Reply with quote

Yes, the "hard" in the title is the rating of the puzzle, not my opinion.

It involves at least a hidden pair. I think I solved it by box-line interactions.

Keith
Back to top
View user's profile Send private message
ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Sun Mar 09, 2008 8:29 pm    Post subject: Reply with quote

Code:
+-------+-------+-------+
| .>1 6 | 4 . . | . .>9 |
| . . . | . 8 h | . . 4 |
| . 3 . | . h 5 | . . . |
+-------+-------+-------+
| . 5 . |>1 . . | . 4*2 |
| .*2 . | 5 . 6 | . 7 . |
| 9 . . | x x 8 | . 5 . |
+-------+-------+-------+
| . . . |>9 . . |*2 1 . |
|*2 . . | . 5 . | . . . |
| 7 . . | x x 3 | 4 6 . |
+-------+-------+-------+

I am with Keith, solving it without pencilmarks is very different and mostly more interesting.
In this early stage (before placing other singles) i saw the hidden pair 19 in box 2 and the x-wing for 2 (yes with pm's i would first see, that the 2's are locked in box 2), so i continued with 2 in r1c6.

So - not challenging, but fun anyway.
Back to top
View user's profile Send private message
keith



Joined: 19 Sep 2005
Posts: 3331
Location: near Detroit, Michigan, USA

PostPosted: Mon Mar 10, 2008 3:15 am    Post subject: Reply with quote

Without pencil marks, I got to here:
Code:
+-------+-------+-------+
| 8 1 6 | 4 . . | 5 . 9 |
| 5 . . | . 8 . | . . 4 |
| 4 3 . | . . 5 | . 8 . |
+-------+-------+-------+
| . 5 . | 1 . . | . 4 2 |
| 1 2 . | 5 . 6 | . 7 . |
| 9 . . | . . 8 | . 5 . |
+-------+-------+-------+
| . . . | 9 . . | 2 1 . |
| 2 . . | . 5 . | . 9 . |
| 7 . . | . . 3 | 4 6 . |
+-------+-------+-------+

After looking for a considerable time, I saw that:

The <7> in B2 is in R1. (Easy to see.)
The <2> in B2 is in C6. (Easy to see.)

Putting them together (without pm's) was not so easy for me: R3C4 must be <6>!

Which places all the values <6>, and solves the puzzle.

Keith

PS: ravel's note is interesting. Since the "hard" puzzles can be solved without X-wings (or UR's, for that matter), I tend not to look for them, and not to use them if I see them.

A personal rule, like the one we all have about stepping on cracks in the sidewalk.
Back to top
View user's profile Send private message
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