View previous topic :: View next topic 
Author 
Message 
geoff h
Joined: 07 Aug 2005 Posts: 58 Location: Sydney

Posted: Sun Aug 07, 2005 8:55 am Post subject: Today's puzzle  Sunday 7th 


I am a new user to this site, but am an experienced sudoku player ( or so I thought !!)
Re today's puzzle. I got stuck and when I asked for a hint from this site, they gave me a 3 in row 3 column 3 of the middle square in the bottom row of the sudoku. I had my options as either a 2 or a 3 for this square, but can't see how the 2 was eliminated!!
Can anyone help?? 

Back to top 


someone_somewhere
Joined: 07 Aug 2005 Posts: 275 Location: Munich

Posted: Sun Aug 07, 2005 9:09 am Post subject: 


Here is a trace to get to this point (the fists numbers in brackets, mean the position on a 9 by 9 board. The upper left cell is (1 1) the bottom right cell is (9 9):
Initial SuDoku Table
0 0 1 0 0 4 7 0 0
0 0 0 7 0 0 0 3 8
6 0 0 9 0 8 4 5 0
5 0 9 0 0 0 0 0 0
0 7 0 0 0 0 0 1 0
0 0 0 0 0 0 3 0 9
0 5 2 1 0 7 0 0 4
7 8 0 0 0 9 0 0 0
0 0 6 8 0 0 5 0 0
(1 1)>8 (3 3)>7 (5 5)>9 unique horizontal
(2 3)>5 (5 9)>5 unique vertical
(6 6)>5 unique vertical
Exclude Nr=1 from (9 9) becasue Nr has to be in (8 7) or (8 9)
Excluded Nr=3 from (4 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (9 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (5 4) because it is in (5 1) and (5 3)
Excluded Nr=3 from (5 6) because it is in (5 1) and (5 3)
Exclude Nr=1 from (4 5) because of numbers= 7 8
Exclude Nr=1 from (4 5) because of numbers= 7 8
Exclude Nr=2 from (4 5) because of numbers= 7 8
Exclude Nr=2 from (4 5) because of numbers= 7 8
Exclude Nr=3 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (4 5) because of numbers= 7 8
Exclude Nr=6 from (4 5) because of numbers= 7 8
Exclude Nr=6 from (4 5) because of numbers= 7 8
(4 6)>1 unique in 3x3
(4 4)>3 unique in 3x3
(9 6)>3 (8 9)>3 unique vertical
Hope I could help you! 

Back to top 


someone_somewhere
Joined: 07 Aug 2005 Posts: 275 Location: Munich

Posted: Sun Aug 07, 2005 9:33 am Post subject: 


Sorry, some small mistakes in some lines.
Here the corrected hint:
(1 1)>8 (3 3)>7 (5 5)>9 unique horizontal
(2 3)>5 (5 9)>5 unique vertical
(6 6)>5 unique vertical
Exclude Nr=1 from (9 9) becasue Nr has to be in (8 7) or (8 9)
Excluded Nr=3 from (4 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (9 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (5 4) because it is in (5 1) and (5 3)
Excluded Nr=3 from (5 6) because it is in (5 1) and (5 3)
Exclude Nr=1 from (4 5) because of numbers= 7 8
Exclude Nr=1 from (6 5) because of numbers= 7 8
Exclude Nr=2 from (4 5) because of numbers= 7 8
Exclude Nr=2 from (6 5) because of numbers= 7 8
Exclude Nr=3 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (6 5) because of numbers= 7 8
Exclude Nr=6 from (4 5) because of numbers= 7 8
Exclude Nr=6 from (6 5) because of numbers= 7 8
LEVEL 5  Exclude based on vertical Exact 2 same Numbers =9
(4 6)>1 unique in 3x3
(4 4)>3 unique in 3x3
(9 6)>3 (8 9)>3 unique vertical 

Back to top 


geoff h
Joined: 07 Aug 2005 Posts: 58 Location: Sydney

Posted: Sun Aug 07, 2005 10:15 am Post subject: Today's Sudoku 


Okay, thanks very much for your reply.
However, still a bit confused!!
I agreed with all your logic movements, except for the following.
Exclude Nr 3 from ( 4 2 ) because it's in ( 1 2 ) and ( 3 2 )
Exclude Nr 3 from ( 9 2 ) because it's in ( 1 2 ) and ( 3 2 )
Exclude Nr 3 from ( 5 4 ) because it's in ( 5 1 ) and ( 5 3 )
Exclude Nr 3 from ( 5 6 ) because it's in ( 5 1 ) and ( 5 3 )
I can't follow the logic of eliminating the Number 3 as you have shown. Are there some hidden pairs or triples that I'm missing?? I have the Number 3 appearing at ( 1 2 ) ( 3 2 ) ( 4 2 ) and ( 9 2 ). So how are you eliminating it as shown?
Thanks 

Back to top 


someone_somewhere
Joined: 07 Aug 2005 Posts: 275 Location: Munich

Posted: Sun Aug 07, 2005 10:31 am Post subject: 


Hi,
the Nr 3 from position (2 cuases exludes of Nr 3 in (2 1) and (2 2). Remains Nr 3 to be in (1 2) or (3 2).
Is this what you were looking for? 

Back to top 


someone_somewhere
Joined: 07 Aug 2005 Posts: 275 Location: Munich

Posted: Sun Aug 07, 2005 10:32 am Post subject: 


I ment position (2 and not (2 ) 

Back to top 


someone_somewhere
Joined: 07 Aug 2005 Posts: 275 Location: Munich

Posted: Sun Aug 07, 2005 10:33 am Post subject: 


Sorry, I try again:
position 2 and 8
It looks like the number 8 followed by the ) is giving us the sign 

Back to top 


Guest

Posted: Sun Aug 07, 2005 11:24 am Post subject: Today's Sudoku 


Yes, thanks for your reply. I already have Nr 3 excluded from ( 2 1 ) and
( 2 2 ). However, I have Nr 3 in ( 1 2 ), ( 3 2 ), ( 4 2 ) and ( 9 2 ) so I don't understand when you say you can exclude Nr 3 from ( 4 2 ) and ( 9 2 ) because it's in ( 1 2 ) and ( 3 2 ).
Sorry for all the questions, but it's really got me beat!! 

Back to top 


geoff h
Joined: 07 Aug 2005 Posts: 58 Location: Sydney

Posted: Sun Aug 07, 2005 11:30 am Post subject: Today's Sudoku 


Sorry, I just had another look and see where I went wrong. Nr 3 has to be in either ( 1 2 ) or ( 3 2 ). Thanks again for your help  it's okay now.
Cheers. 

Back to top 


harps Guest

Posted: Mon Aug 08, 2005 2:40 am Post subject: august 7 


I'm in a quandry 

Back to top 


harps Guest

Posted: Mon Aug 08, 2005 2:41 am Post subject: august 7 


can you give me another push start after these clues above. 

Back to top 


geoff h
Joined: 07 Aug 2005 Posts: 58 Location: Sydney

Posted: Mon Aug 08, 2005 3:02 am Post subject: Sunday's Sudoku (7th August) 


The Number 3 can be excluded from ( 4 2 ) and ( 9 2 ) because it is already in ( 1 2 ) and ( 3 2 ). Nr 3 MUST be in either ( 1 2 ) or ( 3 2 ) because they are the only cells in the first square that support the Number 3. Therefore NR 3 can not appear anywhere else in Column 2.
Similar logic can be applied to the exclusion of Nr 3 from ( 5 4 ) and ( 5 6 ) because Nr 3 MUST be in either ( 5 1 ) or ( 5 3 ) and therefore can
not appear anywhere else in Row 5.
Hope this helps. 

Back to top 


Lena
Joined: 08 Aug 2005 Posts: 1

Posted: Mon Aug 08, 2005 5:35 am Post subject: Sunday's puzzle 


Thanks for the explanation. I needed the same hint. Now it makes sense! 

Back to top 


