The New Sudoku Players' Forum

by **ArkieTech** » Fri Jul 24, 2015 11:06 pm

Code: Select all: *-----------* |6.8|3.4|1.2| |4..|2.5|..3| |...|.9.|...| |---+---+---| |98.|...|.64| |..3|...|2..| |24.|...|.19| |---+---+---| |...|.2.|...| |8..|9.3|..1| |5.2|7.1|4.6| *-----------*

Play/Print this puzzle online

by **Leren** » Fri Jul 24, 2015 11:36 pm

Code: Select all: *---------------------------------------------------------------* | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 16 5 | 689-7 789 3 | | 3 2 157 |b16 9 8 | c567 4 57 | |--------------------+--------------------+---------------------| | 9 8 157 |b15 135 2 | 35-7 6 4 | | 17 1567 3 | 14568 1456 9 | 2 578 578 | | 2 4 56 | 568 356 7 | 358 1 9 | |--------------------+--------------------+---------------------| | 17 1379 1479 |b45 2 6 | 589-7 35789 578 | | 8 67 467 | 9 a45 3 |ca57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | *---------------------------------------------------------------*

ALS XY Wing: (7=4) r8c57 - (4=6) r347c4 - (6=7) r38c7 => - 7 r247c7; stte

Leren

by **SteveG48** » Sat Jul 25, 2015 12:19 am

Code: Select all: *--------------------------------------------------------------------* | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 b16 5 | 6789 789 3 | | 3 2 157 |b16 9 8 |a567 4 57 | *----------------------+----------------------+----------------------| | 9 8 d157 |c15 c135 2 | 35-7 6 4 | | 17 1567 3 | 14568 1456 9 | 2 578 578 | | 2 4 56 | 568 c356 7 | 358 1 9 | *----------------------+----------------------+----------------------| | 17 1379 1479 | 45 2 6 | 5789 35789 578 | | 8 67 467 | 9 45 3 |a57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | *--------------------------------------------------------------------*

(7=56)r38c7 - (6=16)b2p57 - (16=315)b5p128 - (15=7)r4c3 => -7 r4c7 ; stte

by **pjb** » Sat Jul 25, 2015 12:58 am

Code: Select all: 6 59 8 | 3 7 4 | 1 59 2 4 179 179 | 2 16 5 | 6789 789 3 3 2 157 | a16 9 8 | a567 4 57 ------------------------+-----------------------+--------------------- 9 8 157 |ab15 b135 2 |ab35-7 6 4 17 1567 3 | 14568 b1456 9 | 2 578 578 2 4 56 | 568 b356 7 | 358 1 9 ------------------------+-----------------------+--------------------- 17 1379 1479 | 45 2 6 | 5789 35789 578 8 67 467 | 9 b45 3 |ab57 2 1 5 39 2 | 7 8 1 | 4 39 6

(7)r4c7 - (7=6)r38c7 - (6=1)r3c4 - (1)r4c4
(7)r4c7 - (7=5)r8c7 - r7c7 = r456c5 - (5=1)r4c4
Contradiction => -7 r4c7; stte

Phil

BTW this can be transcribed to a chain:
(7=5)r8c7* - r8c5 = r456c5 - (5=6)r34c4 - (56=7)r3c7* => -7 r246c7; stte

by **JC Van Hay** » Sat Jul 25, 2015 6:24 am

(16)r3c4 -> +3r4c7; stte ...

Code: Select all: +----------------+----------------+-------------------+ | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 16 5 | 689-7 789 3 | | 3 2 157 | (16) 9 8 | (567) 4 57 | +----------------+----------------+-------------------+ | 9 8 157 | (15) 135 2 | 3-57 6 4 | | 17 1567 3 | 14568 1456 9 | 2 578 578 | | 2 4 56 | 568 356 7 | 358 1 9 | +----------------+----------------+-------------------+ | 17 1379 1479 | 4(5) 2 6 | 589-7 35789 578 | | 8 67 467 | 9 4(5) 3 | (57) 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | +----------------+----------------+-------------------+ (57=6)r38c7-(6=15)r34c4-5r7c4=5r8c5-(5=7)r8c7 :=> -5r4c7,-7r247c7; stte

by **ArkieTech** » Sat Jul 25, 2015 10:26 am

Code: Select all: *--------------------------------------------------------------------* | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 16 5 | 6789 789 3 | | 3 2 157 |c16 9 8 | 567 4 57 | |----------------------+----------------------+----------------------| | 9 8 157 |c15 135 2 | 357 6 4 | |a17 a1567 3 | 46-158 1456 9 | 2 a578 a578 | | 2 4 56 |c568 356 7 | 358 1 9 | |----------------------+----------------------+----------------------| | 17 1379 1479 |c45 2 6 | 5789 35789 578 | | 8 b67 467 | 9 b45 3 |b57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | *--------------------------------------------------------------------* [(1587=6)r5c1289-(6=4)r8c257-(4=6158)r3467c4]-158r5c4; lclste

by **bat999** » Sat Jul 25, 2015 2:00 pm

Code: Select all: .-------------------.------------------.--------------------. | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 *16 5 | 6789 789 3 | | 3 2 157 | *16 9 8 | *6-57 4 57 | :-------------------+------------------+--------------------: | 9 8 *157 | 15 *135 2 | *357 6 4 | | *17 1567 3 | 14568 1456 9 | 2 578 578 | | 2 4 56 | 568 356 7 | 358 1 9 | :-------------------+------------------+--------------------: | *17 1379 1479 | 45 2 6 | 5789 35789 578 | | 8 *67 *467 | 9 *45 3 | *57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | '-------------------'------------------'--------------------'

(6)r3c7 = r3c4 - (6=1)r2c5 => r4c5<>1
(6=57)r38c7 - (57=3)r4c7 => r4c5<>3
(6=57)r38c7 - (7)r4c7 = r4c3 - (7=1)r5c1 - (1=67)r8c2,r7c1 - (67=4)r8c3 - (4=5)r8c5 => r4c5<>5
=> -5 r3c7, -7 r3c7; stte
8-)

by **daj95376** » Sat Jul 25, 2015 3:45 pm

Code: Select all: +------------------------------------------------------------------------+ | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 16 5 | 6789 789 3 | | 3 2 157 | d16 9 8 | c567 4 57 | |-----------------------+------------------------+-----------------------| | 9 8 157 | 15 135 2 | c357 6 4 | | 17 1567 3 | ae14568 1456 9 | 2 578 578 | | 2 4 56 | be568 356 7 | c358 1 9 | |-----------------------+------------------------+-----------------------| | 17 1379 1479 | 45 2 6 | 5789 35789 578 | | 8 67 467 | 9 45 3 | c57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | +------------------------------------------------------------------------+ # 71 eliminations remain 8r5c4 = r6c4 - (8=6)r3468c7 - r3c4 = (68)r56c4 => -145 r5c4

_

by **eleven** » Sun Jul 26, 2015 6:32 pm

Just for fun:

Code: Select all: +----------------------+----------------------+----------------------+ | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 16 5 | 6789 789 3 | | 3 2 157 | 16 9 8 |#567 4 57 | +----------------------+----------------------+----------------------+ | 9 8 b15*7 | 15 135 2 |a357 6 4 | |c*17 f1567 3 | 14568 1456 9 | 2 578 578 | | 2 4 56 | 568 356 7 | 358 1 9 | +----------------------+----------------------+----------------------+ |d17 1379 1479 | 45 2 6 | 5789 35789 578 | | 8 e*67 467 | 9 45 3 |#57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | +----------------------+----------------------+----------------------+

ALS 567r38c7
5r38c7-r46c7=r5c89
7r38c7-r4c7=*7r4c3-(7=*1)r5c1-(1=7)r7c1-(7=*6)r8c2-(167=5)r5c2
=> r3c7=6 (and r5c45<>5)

by **daj95376** » Sun Jul 26, 2015 11:13 pm

eleven wrote:ALS 567r38c7
5r38c7-r46c7=r5c89
7r38c7-r4c7=*7r4c3-(7=*1)r5c1-(1=7)r7c1-(7=*6)r8c2-(167=5)r5c2
=> r3c7=6 (and r5c45<>5)

Or ...

Code: Select all: (65=7)r38c7-r4c7=*7r4c3-(7=*1)r5c1-(1=7)r7c1-(7=6)r8c2-*(167=5)r5c2-r5c89=r46c7-(5=67)r38c7 => =6 r3c7

_

by **ronk** » Tue Jul 28, 2015 7:12 pm

SteveG48 wrote:
Code: Select all
*--------------------------------------------------------------------* | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 b16 5 | 6789 789 3 | | 3 2 157 |b16 9 8 |a567 4 57 | *----------------------+----------------------+----------------------| | 9 8 d157 |c15 c135 2 | 35-7 6 4 | | 17 1567 3 | 14568 1456 9 | 2 578 578 | | 2 4 56 | 568 c356 7 | 358 1 9 | *----------------------+----------------------+----------------------| | 17 1379 1479 | 45 2 6 | 5789 35789 578 | | 8 67 467 | 9 45 3 |a57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | *--------------------------------------------------------------------*

(7=56)r38c7 - (6=16)b2p57 - (16=315)b5p128 - (15=7)r4c3 => -7 r4c7 ; stte

Congratulations on a complex although valid chain AFAICT. The ALS in b5 is doubly-linked on both sides. One double-link to an LS is located in two columns, and the second double-link is to an AALS in the normal one row. As if that wasn't unusual enough, the digit (1) is a member of both double-links.

by **David P Bird** » Wed Jul 29, 2015 2:31 pm

ronk wrote:
SteveG48 wrote:
Code: Select all
*--------------------------------------------------------------------* | 6 59 8 | 3 7 4 | 1 59 2 | | 4 179 179 | 2 b16 5 | 6789 789 3 | | 3 2 157 |b16 9 8 |a567 4 57 | *----------------------+----------------------+----------------------| | 9 8 d157 |c15 c135 2 | 35-7 6 4 | | 17 1567 3 | 14568 1456 9 | 2 578 578 | | 2 4 56 | 568 c356 7 | 358 1 9 | *----------------------+----------------------+----------------------| | 17 1379 1479 | 45 2 6 | 5789 35789 578 | | 8 67 467 | 9 45 3 |a57 2 1 | | 5 39 2 | 7 8 1 | 4 39 6 | *--------------------------------------------------------------------*

(7=56)r38c7 - (6=16)b2p57 - (16=315)b5p128 - (15=7)r4c3 => -7 r4c7 ; stte

Congratulations on a complex although valid chain AFAICT. The ALS in b5 is doubly-linked on both sides. One double-link to an LS is located in two columns, and the second double-link is to an AALS in the normal one row. As if that wasn't unusual enough, the digit (1) is a member of both double-links.

AFAIAC there is no strong link between Booleans anywhere in sight in the red node.

My best effort at translating this is

Code: Select all: *------------------------------------------------------------* |(1)r3c4 - (1=5)r4c4 | (57=6)r38c7 -(6)r3c4 =| &so [(5)r4c4, (1)r4c5, (3)r6c5] | - (1|5=7)r4c3 |(6)r2c5 - (6=135)r4c45,r6c5 | *------------------------------------------------------------* Steve's Pattern

Notating the chain in reverse we get

(7=1|5)r4c3 - (153=6)r4c45,r6c5 - (6)r2c5 = (6)r3c4 - (6=57)r38c7 => r4c7 <> 7

From left to right this looks OK but from right to left the digits in the box 5 node could be distributed with (5)in r6c5 which wouldn't prevent (5)r4c3 being true.

Website · by **denis_berthier** » Wed Jul 29, 2015 3:01 pm

A solution using only the simplest rules, with no chain of length > 3

*** SudoRules 20.0.s based on CSP-Rules 2.0.s, config = gW+SFin
singles ==> r9c5 = 8, r7c6 = 6, r1c5 = 7, r3c6 = 8, r6c6 = 7, r4c6 = 2, r5c6 = 9, r8c8 = 2, r3c8 = 4, r3c2 = 2, r3c1 = 3
121 candidates, 485 csp-links and 485 links. Density = 6.68%
whip[1]: c8n3{r9 .} ==> r7c7 ≠ 3
x-wing-in-columns: n9{c3 c7}{r2 r7} ==> r7c8 ≠ 9, r7c2 ≠ 9, r2c8 ≠ 9, r2c2 ≠ 9
finned-x-wing-in-rows: n7{r4 r8}{c7 c3} ==> r7c3 ≠ 7, r2c7 ≠ 7, r5c4 ≠ 1
biv-chain[2]: r4n7{c7 c3} - c1n7{r5 r7} ==> r7c7 ≠ 7
whip[2]: r8n5{c5 c7} - b6n5{r4c7 .} ==> r5c5 ≠ 5
biv-chain[3]: r4c4{n1 n5} - b8n5{r7c4 r8c5} - c5n4{r8 r5} ==> r5c5 ≠ 1
whip[1]: r5n1{c2 .} ==> r4c3 ≠ 1
biv-chain[3]: r4c3{n7 n5} - c2n5{r5 r1} - b1n9{r1c2 r2c3} ==> r2c3 ≠ 7
biv-chain[3]: r4c3{n7 n5} - r4c4{n5 n1} - r3n1{c4 c3} ==> r3c3 ≠ 7
singles ==> r2c2 = 7, r2c8 = 8, r8c2 = 6, r6c3 = 6
whip[1]: b1n1{r3c3 .} ==> r7c3 ≠ 1
hidden-pairs-in-a-block: b5{r5c4 r5c5}{n4 n6} ==> r5c4 ≠ 8
stte

by **daj95376** » Wed Jul 29, 2015 3:35 pm

[Withdrawn: I keep trying to treat networks and chains differently, but there's an overlap of chains into networks that trips me up all too often.]

_

by **ronk** » Wed Jul 29, 2015 4:18 pm

daj95376 wrote:
SteveG wrote:
(7=56)r38c7 - (6=16)b2p57 - (16=315)b5p128 - (15=7)r4c3 => -7 r4c7 ; stte

Your chain segment says: r3c7=6 deletes all of the 6s in b2p57 ... followed by the pair 16 remaining in b2c57. This is wrong!

I missed that. The below would be better.

(7=56)r38c7 - (6)r3c4=(16)r3c4,r2c5 - (61=351)r6c5,r4c45 - (15=7)r4c3 => -7 r4c7 ; stte

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