| View previous topic :: View next topic |
| Author |
Message |
storm_norm
Joined: 18 Oct 2007
Posts: 1741
|
 Posted: Fri Oct 17, 2008 9:47 pm Post subject: 10-17 competition |
 |
|
| Code: | 7 . 9|2 . .|1 . 3
. . .|5 . .|. . .
. . 2|. . 6|4 . .
-----+-----+-----
9 8 .|. 4 .|. . .
. . 1|. 2 .|6 . .
. . .|. 7 .|. 9 1
-----+-----+-----
. . 5|3 . .|9 . .
. . .|. . 2|. . .
2 . 4|. . 8|5 . 6 |
enjoy! |
|
| Back to top |
|
 |
Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
|
| Posted: Fri Oct 17, 2008 10:13 pm Post subject: |
|
|
| Two straightforward URs solve it. |
|
| Back to top |
|
|
keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
|
| Posted: Fri Oct 17, 2008 11:27 pm Post subject: |
|
|
| Asellus wrote: | | Two straightforward URs solve it. |
I had an X-wing, XYZ-wing, and an extended (pseudo-cell) XY-wing. No UR's in sight.
Keith |
|
| Back to top |
|
|
arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
|
| Posted: Sat Oct 18, 2008 1:15 am Post subject: |
|
|
I found an x-wing, er, and xyz-wing
did not see a UR  |
|
| Back to top |
|
|
Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
|
| Posted: Sat Oct 18, 2008 4:31 am Post subject: |
|
|
| keith wrote: | | No UR's in sight. |
| arkietech wrote: | | did not see a UR |
Okay... then, what is this? After basics:
| Code: | +---------------+---------------+-----------------+
| 7 6 9 | 2 8 4 | 1 5 3 |
| 13 4 8 | 5 139 179 | 27 6 279 |
|@135 @35 2 | 179 139 6 | 4 78 789 |
+---------------+---------------+-----------------+
| 9 8 367 | 16 4 13 | 237 237 5 |
|@35 @357 1 | 89 2 39 | 6 3478 478 |
| 4 2 36 | 68 7 5 | 38 9 1 |
+---------------+---------------+-----------------+
| 8 17 5 | 3 6 17 | 9 24 24 |
| 6 9 37 | 4 5 2 | 378 1 78 |
| 2 137 4 | 179 19 8 | 5 37 6 |
+---------------+---------------+-----------------+ |
Looks like a Type 6 UR to me. And, it leads immediately here:
| Code: | +---------------+---------------+-----------------+
| 7 6 9 | 2 8 4 | 1 5 3 |
|@13 4 8 | 5 @139 179 | 27 6 279 |
|@13 5 2 | 179 @139 6 | 4 78 789 |
+---------------+---------------+-----------------+
| 9 8 367 | 16 4 13 | 237 237 5 |
| 5 37 1 | 89 2 39 | 6 3478 478 |
| 4 2 36 | 68 7 5 | 38 9 1 |
+---------------+---------------+-----------------+
| 8 17 5 | 3 6 17 | 9 24 24 |
| 6 9 37 | 4 5 2 | 378 1 78 |
| 2 137 4 | 179 #1-9 8 | 5 37 6 |
+---------------+---------------+-----------------+ |
Am I missing something? |
|
| Back to top |
|
|
arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
|
| Posted: Sat Oct 18, 2008 10:57 am Post subject: |
|
|
| Thanks for the help. I did not see it. |
|
| Back to top |
|
|
storm_norm
Joined: 18 Oct 2007
Posts: 1741
|
| Posted: Sat Oct 18, 2008 6:39 pm Post subject: |
|
|
| Code: | 6 9 .|. 4 .|. 3 .
. . .|. . .|. 6 .
2 . .|. 3 .|9 . .
-----+-----+-----
8 . .|. . 5|2 . .
. . .|. . .|. . 9
. . 2|1 . .|. . 7
-----+-----+-----
. . 4|. 8 .|. . 1
. 2 .|. . .|4 . .
. 1 .|. 9 .|. 8 3 |
this is the telegraph puzzle. it breaks down to all bi-value cells except 5. and all but candidate 9 is still unsolved.
its a perfect grid for xy-chain practice.
| Code: | .------------------.------------------.------------------.
| 6 9 17 | 278 4 1278 | 5 3 28 |
| 4 78 3 | 9 5 278 | 1 6 28 |
| 2 58 15 | 68 3 168 | 9 7 4 |
:------------------+------------------+------------------:
| 8 4 9 | 3 7 5 | 2 1 6 |
| 1 67 67 | 48 2 48 | 3 5 9 |
| 35 35 2 | 1 6 9 | 8 4 7 |
:------------------+------------------+------------------:
| 9 36 4 | 5 8 37 | 67 2 1 |
| 37 2 8 | 67 1 367 | 4 9 5 |
| 57 1 56 | 24 9 24 | 67 8 3 |
'------------------'------------------'------------------' |
|
|
| Back to top |
|
|
Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
|
| Posted: Sat Oct 18, 2008 7:44 pm Post subject: |
|
|
| Quote: | | its a perfect grid for xy-chain practice. |
Or for a single UR step. |
|
| Back to top |
|
|
storm_norm
Joined: 18 Oct 2007
Posts: 1741
|
| Posted: Sat Oct 18, 2008 8:09 pm Post subject: |
|
|
| Asellus wrote: | | Quote: | | its a perfect grid for xy-chain practice. |
Or for a single UR step. |
are you in a DP Zone these days? |
|
| Back to top |
|
|
ravel
Joined: 21 Apr 2006
Posts: 536
|
| Posted: Sat Oct 18, 2008 8:13 pm Post subject: |
|
|
| Asellus wrote: | | Or for a single UR step. |
Nice - once more i was too late  |
|
| Back to top |
|
|
tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
|
| Posted: Sun Oct 19, 2008 12:12 am Post subject: |
|
|
I just got on the computer and found this puzzle, and I solved it initially using the two URs noted by Asellus!
I also solved it using an x-wing <3>, a ER <7>, a xy-wing <237> and coloring on <7>.
Nice puzzle.........
Ted |
|
| Back to top |
|
|
Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
|
| Posted: Sun Oct 19, 2008 4:02 am Post subject: |
|
|
| Norm wrote: | | are you in a DP Zone these days? |
Hah! I blame it on ravel!
What I'm tuning into are those DP induced strong links. This one is interesting in that it works the same way an "XZ Wing" ALS method works. Here's the AIC:
(7)r1c4 - (7=1)r1c3 - UR[(1)r1c6=(7)r12c6] - (7)r1c4; r1c4<>7
Short and sweet. In effect, the <1>s are the "shared exclusive" digit and the <7>s the "share common" pincers. |
|
| Back to top |
|
|
storm_norm
Joined: 18 Oct 2007
Posts: 1741
|
| Posted: Sun Oct 19, 2008 7:30 am Post subject: |
|
|
the strong link on 7 inside box 2 is achieved because of the {2,8} dp correct?? because of the 1 not being in r1c6??
this creates the DP situation that states that the 7's must occupy those cells in order to stay out of trouble
this is amazing. I have to keep all of these things in mind when I look for these aic's...whew |
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Sun Oct 19, 2008 12:00 pm Post subject: |
|
|
Alternate perspective:
| Code: | (28) UR [r12c69] => [r1|2c6]=7 -or- [r1c6]=1
[r1|2c6]=7 [r1c4]<>7
[r1 c6]=1 [r1c3]=7 [r1c4]<>7
|
|
|
| Back to top |
|
|
arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
|
| Posted: Sun Oct 19, 2008 2:29 pm Post subject: |
|
|
| daj95376 wrote: | Alternate perspective:
| Code: | (28) UR [r12c69] => [r1|2c6]=7 -or- [r1c6]=1
[r1|2c6]=7 [r1c4]<>7
[r1 c6]=1 [r1c3]=7 [r1c4]<>7
|
|
So simple! Why can't I see them in the wild?  |
|
| Back to top |
|
|
daj95376
Joined: 23 Aug 2008
Posts: 3854
|
| Posted: Sun Oct 19, 2008 5:05 pm Post subject: |
|
|
| arkietech wrote: | | So simple! Why can't I see them in the wild? |
The above perspective on URs is the way I learned to spot them. It works really well when there are only a few non-UR candidates to resolve.
My solver can detect UR Type 1 & 2. I can manually spot a fraction of the remaining URs. However, after others do all of the hard work in finding them, then the eliminations often jump out at me.
I agree with Asellus (in another recent post) that sometimes the chains seem excessively long to show a relationship. I was disappointed in the Players' Forum when one of the last discussions on URs ended with everyone (but me) saying that (practically) anything was allowed when looking to force a relationship. That's when I stopped writing UR modules for my solver and just started relying on resolving them manually (for the few that I can spot).
Other perspectives are so much jibberish to me because I don't understand the underlying criteria -- especially when someone starts talking about cases where the UR candidates must be true outside the UR pattern. It seems that they can be restricted to certain cells, but I've never seen an explanation on how to determine which cells. I keep planning to work it out for myself, but I haven't done so, yet. |
|
| Back to top |
|
|
arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
|
| Posted: Sun Oct 19, 2008 6:58 pm Post subject: |
|
|
I use a solver to help me learn to spot solutions. In this case the ur 28 was certainly easy to spot. Finding something to eliminate or set is much more difficult. I was looking at the cells r12c6 to find eliminations. Then Block 2 then col 6. I totally missed the 17 pair in row 1 opting rather to take on the next ur. I have just got to broaden my horizons and what I look for. 
Thanks for the help daj9536 |
|
| Back to top |
|
|
Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
|
| Posted: Sun Oct 26, 2008 4:56 am Post subject: |
|
|
| I used an M-Wing on 37, a Type 6 UR on 35 and a Type 2 on 13. |
|
| Back to top |
|
|
ravel
Joined: 21 Apr 2006
Posts: 536
|
| Posted: Sun Oct 26, 2008 3:55 pm Post subject: |
|
|
| daj95376 wrote: | | ... when someone starts talking about cases where the UR candidates must be true outside the UR pattern. |
Though its easier here to do it from the extra candidates as you showed it, you can make the same elimination with the "outside" candidates here:
| Code: | .------------------.------------------.------------------.
| 6 9 17 |#278 4 *1278 | 5 3 *28 |
| 4 #78 3 | 9 5 *278 | 1 6 *28 |
| 2 58 15 | 68 3 168 | 9 7 4 |
:------------------+------------------+------------------:
| 8 4 9 | 3 7 5 | 2 1 6 |
| 1 67 67 | 48 2 48 | 3 5 9 |
| 35 35 2 | 1 6 9 | 8 4 7 |
:------------------+------------------+------------------:
| 9 36 4 | 5 8 37 | 67 2 1 |
| 37 2 8 | 67 1 367 | 4 9 5 |
| 57 1 56 | 24 9 24 | 67 8 3 |
'------------------'------------------'------------------'
|
To avoid the 28 DP at least one of 2 and 8 must be somewhere else in rows 12.
So either r1c4 must be 2 or 8 or r2c2 must be 8, which implies r1c3=7.
In all 3 cases r1c4 cant be 7.
The same could be done with the 2 boxes. There are 3 cells outside that contain 2 or 8. Once again r1c4 (28) and r3c46 have a 8, both imply r2c2=8 and r1c3=7.
But i cannot see something useful from the outside cells in the columns (r35c6=8 or r9c6=2).
[Added:]This point of view sometimes is useful for players not using pencilmarks, though its a bit complicated in this case.
| Code: | *-----------------------*
| 6 9 . | * 4 X | 5 3 28|
| 4 * 3 | 9 5 X | 1 6 28|
| 2 . . | . 3 . | 9 7 4 |
|-------+-------+-------|
| 8 4 9 | 3 7 5 | 2 1 6 |
| 1 . . |48 2 48| 3 5 9 |
| . . 2 | 1 6 9 | 8 4 7 |
|-------+-------+-------|
| 9 . 4 | 5 8 . | . 2 1 |
| . 2 8 | . 1 . | 4 9 5 |
| . 1 . |24 9 24| . 8 3 |
*-----------------------*
|
With the hidden pair 24 in in r9c46 you have all what is needed to place 7 in r8c4 - no need to pencil in the candidates in r12c6. |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
