another puzzle for solve

Post the puzzle or solving technique that's causing you trouble and someone will help

another puzzle for solve

Postby fredooi » Mon Aug 11, 2008 4:54 am

it's me again....this is from sunday's paper, neither me nor my bro are able to solve it.

Without pencilmarks:
Code: Select all
. 4 6 | 2 . 5 | 8 7 .
. . 7 | . 8 4 | 1 . .
8 3 . | . 7 9 | 2 4 .
------+-------+------
5 . . | 4 . 7 | . . 1
7 1 . | . . 6 | 4 2 .
4 . . | . . 3 | . . 7
------+-------+------
. . . | 7 4 8 | . 6 .
3 7 8 | 9 6 2 | 5 1 4
6 . 4 | . . 1 | 7 . .





With pencilmarks:
Code: Select all
19    4      6     | 2    13      5   | 8      7      39
29    259    7     | 36   8       4   | 1      359    3569
8     3      15    | 16   7       9   | 2      4      56
-------------------+------------------+-------------------
5     68    239    | 4    29      7   | 369   389     1
7     1     39     | 58   59      6   | 4     2       3589
4     68    29     | 158  1259    3   | 69    589     7
-------------------+------------------+-------------------
129   259   15     | 7    4       8   | 39    6       239
3     7     8      | 9    6       2   | 5     1       4
6     29    4      | 35   35      1   | 7     89      289 
fredooi
 
Posts: 14
Joined: 04 August 2008

Postby Pat » Mon Aug 11, 2008 7:09 am

fredooi wrote:this is from sunday's paper

Code: Select all
 . 4 6 | 2 . 5 | 8 7 .
 . . 7 | . 8 4 | 1 . .
 8 3 . | . 7 9 | 2 4 .
-------+-------+------
 5 . . | 4 . 7 | . . 1
 7 1 . | . . 6 | 4 2 .
 4 . . | . . 3 | . . 7
-------+-------+------
 . . . | 7 4 8 | . 6 .
 3 7 8 | 9 6 2 | 5 1 4
 6 . 4 | . . 1 | 7 . .



Code: Select all
19    4      6     | 2    13      5   | 8      7      39
29    259    7     | 36   8       4   | 1      359    3569
8     3      15    | 16   7       9   | 2      4      56
-------------------+------------------+-------------------
5     68    239    | 4    29      7   | 369   389     1
7     1     39     | 58   59      6   | 4     2       3589
4     68    29     | 158  1259    3   | 69    589     7
-------------------+------------------+-------------------
129   259   15     | 7    4       8   | 39    6       239
3     7     8      | 9    6       2   | 5     1       4
6     29    4      | 35   35      1   | 7     89      289 




which newspaper is that?
    too tough for me -- needs "forcing chains"
User avatar
Pat
 
Posts: 3462
Joined: 18 July 2005

Postby Carcul » Mon Aug 11, 2008 8:54 am

Code: Select all
 *----------------------------------------------------------*
 | 19    4     6     | 2     13    5     | 8     7     39   |
 | 29    259   7     | 36    8     4     | 1     359   3569 |
 | 8     3     15    | 16    7     9     | 2     4     56   |
 |-------------------+-------------------+------------------|
 | 5     68    239   | 4     29    7     | 369   389   1    |
 | 7     1     39    | 58    59    6     | 4     2     3589 |
 | 4     68    29    | 158   1259  3     | 69    589   7    |
 |-------------------+-------------------+------------------|
 | 129   259   15    | 7     4     8     | 39    6     239  |
 | 3     7     8     | 9     6     2     | 5     1     4    |
 | 6     29    4     | 35    35    1     | 7     89    289  |
 *----------------------------------------------------------*


Let's start by noting that the cell [r6c5] behaves like a bivalue cell (1,5), because of [r6c5]=1(or 5)|=3=[r4c3]-3-[r5c3]=3=[r5c9]-3-[r1c9]=3=
=[r1c5]-3-[r9c5]-5-[r45c5]-2,9-[r6c5]. Therefore we have

[r7c2]=5=[r2c2]-5-[r2c8]=5=[r6c8]-5-[r6c5]-1-[r1c5]=1=[r3c4]-1-
-[r3c3]=1=[r7c3]=5=[r7c2],

and so r7c2=5 which solves the puzzle (together with a trivial BUG).
Carcul
 
Posts: 724
Joined: 04 November 2005

Postby fredooi » Tue Aug 12, 2008 3:48 am

hi carcul, i can't understand what you are writing, and i feel that u are not doing any logical deduction in it, can you please explain it further?

well i am from malaysia and this puzzle is from the star newspaper, which is very popular in northern peninsular.
fredooi
 
Posts: 14
Joined: 04 August 2008

Re: another puzzle for solve

Postby Luke » Tue Aug 12, 2008 3:58 am

A different approach...

Code: Select all
19    4      6     | 2    13      5   | 8      7      39
29    259    7     | 36   8       4   | 1      359    3569
8     3      15    | 16   7       9   | 2      4      56
-------------------+------------------+-------------------
5     68    *239   | 4    *29     7   | 369   389     1
7     1     39     | 58   59      6   | 4     2       3589
4     68    *29    | 158  *1259   3   | 69    589     7
-------------------+------------------+-------------------
129   259   15     | 7    4       8   | 39    6       239
3     7     8      | 9    6       2   | 5     1       4
6     29    4      | 35   35      1   | 7     89      289

Another x-wing overlay on a Unique Rectangle with diagonal bivalues, like this puzzle from last week. "The diagonal pairs must have the x-wing component," so both r4c5 and r6c3 = 2. This opens up a couple simple wings, then a XY chain or two brings it home.

I'm betting that somehow Glyn will make better use of this UR... <throwing down gauntlet>:)
User avatar
Luke
2015 Supporter
 
Posts: 435
Joined: 06 August 2006
Location: Southern Northern California

Postby fredooi » Tue Aug 12, 2008 4:28 am

how do u make sure that r4c5 and r6c3 = 2, when it could be r4c3=r6c5=2?
fredooi
 
Posts: 14
Joined: 04 August 2008

Postby Jean-Christophe » Tue Aug 12, 2008 4:44 am

Hi,

These are uniqueness techniques.
The x-wing overlay on a Unique Rectangle is AKA Uniqueness Test 6
There two such Uniqueness Test 6 in your puzzle.
At the end, there is BUG+1 (Bivalue Universal Grave)

It can be solved without using uniqueness techniques, but then requires more forcing chains, wings...
Jean-Christophe
 
Posts: 149
Joined: 22 January 2006

Postby storm_norm » Tue Aug 12, 2008 4:58 am

luke I am going to steal your grid.

this isn't any faster but if you start with a move like the one below then you exploit those {2,9} cells a little differently, as a w-wing.

(9=6)r6c7-(6=8)r6c2-(8)r4c2=(8)r4c8-(8=9)r9c8; means that r7c7 can't be a 9

after you clean up, the grid looks like this

Code: Select all
.------------------.------------------.------------------.
| 19    4     6    | 2     13    5    | 8     7     39   |
| 29    259   7    | 36    8     4    | 1     359   3569 |
| 8     3     15   | 16    7     9    | 2     4     56   |
:------------------+------------------+------------------:
| 5     68   -239  | 4    *29    7    | 69    38    1    |
| 7     1     39   | 58    59    6    | 4     2     358  |
| 4     68   *29   | 158  1-259  3    | 69    58    7    |
:------------------+------------------+------------------:
| 129   259   15   | 7     4     8    | 3     6     29   |
| 3     7     8    | 9     6     2    | 5     1     4    |
| 6     29    4    | 35    35    1    | 7     89    289  |
'------------------'------------------'------------------'


now those {2,9} cells used as a w-wing can eliminate the two's in r4c3 and r6c5...

(2=9)r6c3-(9)r5c3=(9)r5c5-(9=2)r4c5; r4c3 and r6c5 cannot be 2

and then you can go on to use some xy-chains, and whatever else your heart desires, its all in there.
storm_norm
 
Posts: 85
Joined: 27 February 2008

Postby Luke » Tue Aug 12, 2008 5:08 am

Jean-Christophe wrote:There two such Uniqueness Test 6 in your puzzle.

Could you reveal the other? I missed it.
User avatar
Luke
2015 Supporter
 
Posts: 435
Joined: 06 August 2006
Location: Southern Northern California

Postby fredooi » Tue Aug 12, 2008 8:16 am

thank you guys! now i understand the meaning of uniqueness test. i think i can solve most puzzles that i couldn't previously now.

anyway, i'm still working on this puzzle, to see whether it's really invalid or not...it already takes me some time to understand the theories...
fredooi
 
Posts: 14
Joined: 04 August 2008

Postby Pat » Tue Aug 12, 2008 8:35 am

fredooi wrote:
i am from Malaysia
and this puzzle is from the Star newspaper,
which is very popular in northern peninsular



thanks


fredooi wrote:
i'm still working on this puzzle, to see whether it's really invalid or not



just to clarify,
the puzzle is definitely valid,
it has exactly one answer
User avatar
Pat
 
Posts: 3462
Joined: 18 July 2005

Postby Jean-Christophe » Tue Aug 12, 2008 9:39 am

Luke451 wrote:
Jean-Christophe wrote:There two such Uniqueness Test 6 in your puzzle.

Could you reveal the other? I missed it.


Here are two WT from my soft JSudoku, with and without uniqueness. Not sure all the wings are required...

Code: Select all
With uniqueness:
Uniqueness Test 6: (29)UR:r46c35 & X-Wing on 2 -> r4c5, r6c3 = 2
XYZ-Wing on 9 with pivot r4c7, pincers r4c3 & r6c7 -> r4c8 <> 9
XY-Wing on 3 with pivot r9c8, pincers r4c8 & r7c7 -> r4c7 <> 3
r7c7 = 3 (hidden single in c7)
r46c7 forms a naked Pair on {69} within n6 -> not elsewhere in n6
W-Wing with strong link on 9 in r1, r2c1 & r7c9 = {29} -> r7c1 <> 2
r2c1 = 2 (hidden single in c1)
XYZ-Wing on 9 with pivot r2c8, pincers r1c9 & r2c2 -> r2c9 <> 9
Uniqueness Test 6: (29)UR:r79c29 & X-Wing on 2 -> r7c9, r9c2 = 2
XY-Chain on 3 with 6 cells (3=9)r1c9-(9=1)r1c1-(1=3)r1c5-(3=5)r9c5-(5=9)r5c5-(9=3)r5c3 -> r5c9<>3
Singles
r2c28 forms a naked Pair on {59} within r2 -> not elsewhere in r2
BUG+1 -> r6c4 = 5

Without uniqueness:
XY-X-Chain on 9|6 with 1 cells 2 links (9=3)r1c9-(3)r1c5=(3)r2c4-(6)r2c4=(6)r2c9 -> r2c9<>9
XY-X-Chain on 8|9 with 2 cells 1 links (8)r4c8=(8)r4c2-(8=6)r6c2-(6=9)r6c7 -> r4c8<>9
XY-Wing on 3 with pivot r9c8, pincers r4c8 & r7c7 -> r4c7 <> 3
r7c7 = 3 (hidden single in c7)
r46c7 forms a naked Pair on {69} within n6 -> not elsewhere in n6
W-Wing with strong link on 9 in r1, r2c1 & r7c9 = {29} -> r7c1 <> 2
r2c1 = 2 (hidden single in c1)
W-Wing with strong link on 9 in r5, r6c3 & r4c5 = {29} -> r4c3, r6c5 <> 2
r6c3 = 2 (hidden single in n4)
r4c5 = 2 (hidden single in n5)
XY-Chain on 3 with 6 cells (3=9)r1c9-(9=1)r1c1-(1=3)r1c5-(3=5)r9c5-(5=9)r5c5-(9=3)r5c3 -> r5c9<>3
Singles
r2c28 forms a naked Pair on {59} within r2 -> not elsewhere in r2
XY-Chain on 5 with 4 cells (5=9)r2c8-(9=3)r1c9-(3=1)r1c5-(1=5)r6c5 -> r6c8<>5
Singles


BTW Selamat datang fredooi:)
Jean-Christophe
 
Posts: 149
Joined: 22 January 2006

Postby fredooi » Tue Aug 12, 2008 10:44 am

hi Jean-Christophe! i managed to solve the puzzle using uniqueness method. now trying to work with the non uniqueness method.
fredooi
 
Posts: 14
Joined: 04 August 2008


Return to Help with puzzles and solving techniques

cron