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 

Free Press July 20, 2014

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other puzzles
View previous topic :: View next topic  
Author Message
Clement



Joined: 24 Apr 2006
Posts: 1110
Location: Dar es Salaam Tanzania

PostPosted: Sun Jul 20, 2014 5:14 pm    Post subject: Free Press July 20, 2014 Reply with quote

Code:

+-------+-------+-------+
| . . . | . 4 . | . . 1 |
| 1 . . | 5 . . | . . . |
| 9 . 6 | . 2 . | 7 4 . |
+-------+-------+-------+
| . . 8 | . . . | . . 4 |
| . 1 7 | . . . | 8 2 . |
| 4 . . | . . . | 3 . . |
+-------+-------+-------+
| . 7 5 | . 9 6 | 2 . 8 |
| . . . | . . 1 | . . 7 |
| 6 . . | . 8 . | . . . |
+-------+-------+-------+

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



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

PostPosted: Sun Jul 20, 2014 8:18 pm    Post subject: Reply with quote

Code:
 *--------------------------------------------------*
 | 7    28   23   | 36   4    39   | 569  568  1    |
 | 1   a48   3-4  | 5    67   379  | 69  a68   2    |
 | 9    5    6    | 1    2    8    | 7    4    3    |
 |----------------+----------------+----------------|
 | 2    3    8    | 67   67   5    | 1    9    4    |
 | 5    1    7    | 9    3    4    | 8    2    6    |
 | 4    6    9    | 8    1    2    | 3    7    5    |
 |----------------+----------------+----------------|
 | 3    7    5    | 4    9    6    | 2    1    8    |
 | 8    9   b24   |b23   5    1    | 46  b36   7    |
 | 6    2-4  1    | 237  8    37   | 45   35   9    |
 *--------------------------------------------------*
(4=6)r2c28-(6=4)r8c348 => -4r2c3,r9c2; ste
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Sun Jul 20, 2014 11:31 pm    Post subject: Reply with quote

Code:

+---------+------------+-----------+
| 7 28 23 | 36  4  39  | 569 568 1 |
| 1 48 34 | 5   67 379 | 69  68  2 |
| 9 5  6  | 1   2  8   | 7   4   3 |
+---------+------------+-----------+
| 2 3  8  | 67  67 5   | 1   9   4 |
| 5 1  7  | 9   3  4   | 8   2   6 |
| 4 6  9  | 8   1  2   | 3   7   5 |
+---------+------------+-----------+
| 3 7  5  | 4   9  6   | 2   1   8 |
| 8 9  24 | 23  5  1   | 46  36  7 |
| 6 24 1  | 237 8  37  | 45  35  9 |
+---------+------------+-----------+

Play this puzzle online at the Daily Sudoku site

If there's a pattern-based move in there, it escaped me. XY-Chain.

(4=2)r8c3-(2=3)r8c4-(3=6)r8c8-(6=8)r2c8-(8=4)r2c2=>r9c2<>4
Back to top
View user's profile Send private message
Clement



Joined: 24 Apr 2006
Posts: 1110
Location: Dar es Salaam Tanzania

PostPosted: Mon Jul 21, 2014 12:22 pm    Post subject: Free Press July 20, 2014 Reply with quote

It should be July 18, 2014
Code:

+---------+------------+-----------+
| 7 28 23 | 36  4  39  | 569 568 1 |
| 1 b48 34 | 5   67 379 | 69  a68  2 |
| 9 5  6  | 1   2  8   | 7   4   3 |
+---------+------------+-----------+
| 2 3  8  | 67  67 5   | 1   9   4 |
| 5 1  7  | 9   3  4   | 8   2   6 |
| 4 6  9  | 8   1  2   | 3   7   5 |
+---------+------------+-----------+
| 3 7  5  | 4   9  6   | 2   1   8 |
| 8 9  d24 | e23  5  1   | 46  f3-6  7 |
| 6 c24 1  | 237 8  37  | 45  35  9 |
+---------+------------+-----------+
(6=8)r2c8-(8=4)r2c2-(4=2)r2c9-r8c3=(2-3)r8c4=r8c8; r8c8<>6; stte.
Back to top
View user's profile Send private message AIM Address
dongrave



Joined: 06 Mar 2014
Posts: 563

PostPosted: Sat Jul 26, 2014 2:50 pm    Post subject: Reply with quote

Hi, could someone translate the notation in Marty's or Clement's solutions for me - or direct me to a link that explains it? Thanks in advance! Don.
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Sat Jul 26, 2014 3:10 pm    Post subject: Reply with quote

Don, you can take a look at this gibberish,

http://www.sudocue.net/eureka-notation.php

And then i can try explaining it in English.
Back to top
View user's profile Send private message
dongrave



Joined: 06 Mar 2014
Posts: 563

PostPosted: Sun Jul 27, 2014 12:01 am    Post subject: Reply with quote

Thanks Marty! Looks like good reading. Let me go over it until I understand it and I'll let you know if I have any questions. Don.
Back to top
View user's profile Send private message
dongrave



Joined: 06 Mar 2014
Posts: 563

PostPosted: Sun Jul 27, 2014 3:49 pm    Post subject: Reply with quote

Hi again Marty! Well, I read it over and I understand it - but oh my God, who on earth designed this god-awful notation? 'P=Q' is used to indicate that P and Q are not equal? What? Really? And then those non-intuitive contractions enclosed in parentheses? And if shortening expressions was their main concern, they why not replace r#c# with a1 -> i9 (similar to chess notation). Is it just me? It seems like they went out of their way to make this as cryptic and confusing as possible. I guess I would have expected it to resemble the notation used in symbol logic or mathematical set theory! (I think I'll stick to English for now.) Thanks, Don.
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Sun Jul 27, 2014 5:31 pm    Post subject: Reply with quote

Strong inference means both can't be false, i.e., one or the other must be true.

Weak inference means both can't be true.

Chains must be written with alternating strong and weak inferences. The last number in one term is the first number in the next term.

Clement's chain: (6=8)r2c8-(8=4)r2c2-(4=2)r2c9-r8c3=(2-3)r8c4=r8c8; r8c8<>6

R2c8 must be 6 or 8. The number before the equal sign means if the cell is not that number. So in r2c8, if not 6 it must be 8. If 8, then r2c4 must be 4. Then r2c9 must be 2 if r2c2 is 4. If r2c9 is 2, then r8c3 is not 2 and r8c4 must be 2. Since r8c4 is 2, it can't be 3 and if it's not 3, then r8c8 must be 3.

So we've seen that if r2c8 is 8, then r8c8 must be 3. But if r2c8 is not 8, it must be 6, meaning r8c8 is 3. Thus, either way, r8c8 is 3 or unequal to 6.

Hope that's clear.
Back to top
View user's profile Send private message
dongrave



Joined: 06 Mar 2014
Posts: 563

PostPosted: Fri Aug 01, 2014 2:36 am    Post subject: Reply with quote

Hi Marty, I take it from your response that it's just me that despises this Eureka notation. I like the way you made your point without even stating it. Don't others find this notation as cryptic and confusing as I did when they first see it? Oh well, if it's just me, then I'm going to go over this until it becomes second nature. Thanks again, Don.
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Fri Aug 01, 2014 3:43 am    Post subject: Reply with quote

dongrave wrote:
Hi Marty, I take it from your response that it's just me that despises this Eureka notation. I like the way you made your point without even stating it. Don't others find this notation as cryptic and confusing as I did when they first see it? Oh well, if it's just me, then I'm going to go over this until it becomes second nature. Thanks again, Don.


Well, Don, whether one loves Eureka or hates it, it's part of the game and those who don't know it are at a big disadvantage because it's the standard way that players describe their moves, the lingua franca of Sudoku, so to speak.

I learned Eureka years too late. I was getting sick of having to ask about someone's moves because I didn't understand the notation. Two years ago a fellow player who I've known for years put up with a lot of stupid questions and took the time to teach it to me for which I'm extremely grateful.

Quote:
Don't others find this notation as cryptic and confusing as I did when they first see it?


Sure. One can't just look at it and understand it right off the bat; you're far from the only one.
Back to top
View user's profile Send private message
keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Sat Aug 09, 2014 2:32 am    Post subject: Reply with quote

Uniqueness (BUG+3):
Code:
+-------------+-------------+-------------+
| 7   28  23  |C36  4   39  |A569 B568 1  |
| 1   48  34  | 5   67  379 | 69  68  2   |
| 9   5   6   | 1   2   8   | 7   4   3   |
+-------------+-------------+-------------+
| 2   3   8   | 67  67  5   | 1   9   4   |
| 5   1   7   | 9   3   4   | 8   2   6   |
| 4   6   9   | 8   1   2   | 3   7   5   |
+-------------+-------------+-------------+
| 3   7   5   | 4   9   6   | 2   1   8   |
| 8   9   24  |2-3  5   1   | 46  36  7   |
| 6   24  1   |D237 8   37  | 45  35  9   |
+-------------+-------------+-------------+

A or B is 6, implying C is 3,

OR

D is 3,

taking out 3 in R8C4.

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