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3 Mar, 2006 "Nightmare"

 
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David Bryant
Gold Member
Gold Member


Joined: 20 Jan 2006
Posts: 86
Location: Denver, Colorado

PostPosted: Fri Mar 03, 2006 4:25 pm    Post subject: 3 Mar, 2006 "Nightmare" Reply with quote

Ruud's puzzles have been pretty tough lately, and I haven't been able to employ my favorite technique
for a week or so.

Today's puzzle is different. After completing 18 cells and making a few eliminations with simple coloring,
I found a "5-star constellation" that allowed me to set the value at r6c8. The rest of the puzzle was simple.

I'm just curious if anyone else spotted that pattern. dcb
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keith
Hooked
Hooked


Joined: 07 Feb 2006
Posts: 35
Location: near Detroit, Michigan, USA

PostPosted: Sat Mar 04, 2006 12:22 am    Post subject: On a wing ... Reply with quote

David,

I got to this position:

Code:



+-------------------+-------------------+-------------------+
| 2489  2489  48    | 2589  7     6     | 3     1     45    |
| 2689  5     1     | 4     238   2389  | 269   7     69    |
| 3     2469  7     | 259   1     259   | 269   8     45    |
+-------------------+-------------------+-------------------+
| 49    1     34    | 6     23    7     | 5     29    8     |
| 568   368   3568  | 1     9     23    | 4     26    7     |
| 7     69    2     | 58    58    4     | 69    3     1     |
+-------------------+-------------------+-------------------+
| 1     3468  34568 | 3589  458   589   | 7     69    2     |
| 246   7     346   | 239   24    1     | 8     5     69    |
| 258   28    9     | 7     6     258   | 1     4     3     |
+-------------------+-------------------+-------------------+



Then, not in order, two X-wings and three XY-wings will solve the puzzle.

Keith
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David Bryant
Gold Member
Gold Member


Joined: 20 Jan 2006
Posts: 86
Location: Denver, Colorado

PostPosted: Sat Mar 04, 2006 1:13 am    Post subject: We're talking about 2 different puzzles ... Reply with quote

Hi, Keith!

You're ahead of me ... I was talking about the "nightmare" for Friday, March 3. You've apparently worked the puzzle for Saturday, March 4, which I haven't even attempted yet!

The puzzle I was talking about looked like this to start.
Code:
.1.....74
.5..8.3..
2....9...
..65.....
74..1..38
.....41..
...2....3
..4.7..8.
63.....9.

Big time zone differences are probably to blame for the miscommunication. I think Ruud is eight hours ahead of MST (mountain
time, where I live) and seven hours ahead of CST (central time in Detroit). He always updates his puzzle pretty promptly at
midnight (for him) -- so if you grab "today's" puzzle after 5:00 pm you'll actually be getting "tomorrow's" puzzle. Ain't globalization grand?

Sorry about the confusion -- thanks for the hint on "tomorrow's" puzzle, though. dcb Very Happy
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David Bryant
Gold Member
Gold Member


Joined: 20 Jan 2006
Posts: 86
Location: Denver, Colorado

PostPosted: Sun Mar 05, 2006 12:35 am    Post subject: Saturday, 4 Mar "Nightmare" Reply with quote

Hi, Keith!

I've finally worked through the "Nightmare" for Saturday, March 4th. I arrived at practically the same position you did, but managed to eliminate three possible occurrences of the digit "6" (at r2c7, r5c2, & r7c2) by simple coloring on "6" before I located the three XY-Wings.
Code:
2489  2489   48   2589    7     6     3     1    45
2689    5     1     4    238  2389   29     7    69
  3   2469    7    259    1    259   269    8    45
 49     1    34     6    23     7     5    29     8
 568   38   3568    1     9    23     4    26     7
  7    69     2    58    58     4    69     3     1
  1    348  34568 3589   458   589    7    69     2
 246    7    346   239   24     1     8     5    69
 258   28     9     7     6    258    1     4     3

Now a series of inter-dependent "XY-Wings" solves the puzzle.

1. XY-Wing proceeding from {3, 8} at r5c2 eliminates "2" at r9c6.
2. The "2" in row 8 lies in bottom center 3x3 box; eliminate "2" at r8c1.
3. XY-Wing proceeding from {2, 3} at r4c5 eliminates "4" at r8c3.
4. XY-Wing proceeding from {3, 6} at r8c3 eliminates "4" at r4c1.

And with r4c1 = 9 the rest of the puzzle crumbles like a piece of cheese. dcb
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dejsmith
Rookie
Rookie


Joined: 06 Mar 2006
Posts: 5
Location: San Ramon, CA, USA

PostPosted: Wed Mar 08, 2006 8:31 pm    Post subject: Only Needed an X Wing Reply with quote

Hi David

After hearing you & Keith rave about this site for awhile, I finally decided to give it a try. The first puzzle I tried took me 2 hours. The next, after more time than that, I needed help from your inputs on this forum. That should give Ruud a nice chuckle. Anyway, this particular one only required an X Wing on 6s in Rows 2&5 for me. I am enjoying this site very much; & I am sure it will get me much better...eventually!!! And, in answer to your original question; No, I did not notice the constellation; but I am not going back to look for it. Ha, ha. Too many other puzzles to work.

Thanks...Dave
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