The New Sudoku Players' Forum

[EnderGT]

And this one has me stuck.

Code: Select all

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


Here's where I left off:

Code: Select all

 +-------------------+-------------------+-------------------+
 | 1     467   27    | 24    9     246   | 8     3     5     |
 | 28    9     5     | 3     7     268   | 4     12    126   |
 | 248   468   3     | 1248  16    5     | 7     29    269   |
 |-------------------+-------------------+-------------------|
 | 347   5     78    | 6     234   9     | 1     248   234   |
 | 6     2     19    | 14    8     34    | 5     7     349   |
 | 34    148   189   | 5     1234  7     | 6     2489  2349  |
 |-------------------+-------------------+-------------------|
 | 278   178   1278  | 9     46    468   | 3     5     14    |
 | 9     3     4     | 7     5     1     | 2     6     8     |
 | 5     18    6     | 248   34    2348  | 9     14    7     |
 +-------------------+-------------------+-------------------+


I'm still learning some of the more advanced techniques, but I can't spot a Fish, a chain, etc in this one.

[Steve R]

The best I can come up with is
r4c3 =7 ==> r4c1 ≠ 7 ==> r7c1 = 7 ==> r7c3 = 2 ==> r1c3 = 7==> r4c3 ≠ 7.

Steve

[hobiwan]

My solver finds a Finned Franken Swordfish candidate 4: r5b29/c469 fin[r9c8] => [r9c46]<>4 (how someone should find this with pencil and paper is beyond my imagination...)

Unfortunately this doesn't really advance the puzzle, unlike Steve R's elimination.

For people like me, who like absurdities, there is also a Finned Mutant Leviathan candidate 4: r13b45689/r469c469b1 fin[r7c5] => [r9c46]<>4 (of course some people would call it "sashimi" and others would not call it a fish at all ).

[ArkieTech]

found an ALS (I think) that will lead to an XY-wing later on.

Code: Select all

 +-------------------+-------------------+-------------------+
 | 1     67-4  27    | 24    9     246   | 8     3     5     |
 |A28    9     5     | 3     7     268   | 4     12    126   |
 |A248   68-4  3     | 1248  16    5     | 7     29    269   |
 |-------------------+-------------------+-------------------|
 | 37-4  5     78    | 6     234   9     | 1     248   234   |
 | 6     2     19    | 14    8     34    | 5     7     349   |
 | 3-4  B148   189   | 5     1234  7     | 6     2489  2349  |
 |-------------------+-------------------+-------------------|
 |A278  B178   1278  | 9     46    468   | 3     5     14    |
 | 9     3     4     | 7     5     1     | 2     6     8     |
 | 5    B18    6     | 248   34    2348  | 9     14    7     |
 +-------------------+-------------------+-------------------+
 ALS A(2478) B(1478) common 7  => r46c1<>4 =>r23c2<>4


dan

[Mike Barker]

Nicely done.

[StrmCkr]

i found theses.in order of application.

DEATH BLOSSOM: ([ALS:r2c1] and [ALS:r4c3|r5c3|r6c3]) + Stem:r1c3 means 8 can be removed from r4c1

DEATH BLOSSOM: ([ALS:r2c1] and [ALS:r4c3|r5c3|r6c3]) + Stem:r1c3 means 8 can be removed from r6c1

DEATH BLOSSOM: ([ALS:r1c3|r1c4] and [ALS:r5c3|r6c2|r6c3]) + Stem:r4c3 means 4 can be removed from r1c2

DEATH BLOSSOM: ([ALS:r1c3|r2c1] and [ALS:r4c1|r6c1]) + Stem:r3c1 means 7 can be removed from r4c3

solves some singles. than

DEATH BLOSSOM: ([ALS:r1c4] and [ALS:r7c1|r7c3|r7c5|r7c6]) + Stem:r1c3 means 4 can be removed from r9c4

DEATH BLOSSOM: ([ALS:r2c1] and [ALS:r2c8|r3c9]) + Stem:r3c2 means 2 can be removed from r2c9

DEATH BLOSSOM: ([ALS:r2c1] and [ALS:r3c5|r3c9]) + Stem:r3c2 means 2 can be removed from r2c8

than it solves as singles.

[ncantoral]

after Steve's AIC there is a xy-wing {2,6,8} needed to complete it.

I think before the AIC there is a xy-wing present.

[EnderGT]

The best I can come up with is
r4c3 =7 ==> r4c1 ≠ 7 ==> r7c1 = 7 ==> r7c3 = 2 ==> r1c3 = 7==> r4c3 ≠ 7.

Steve

Thanks, this didn't solve the puzzle, but did advance it to where I could find an XY-wing (I think someone mentioned it above?) that solved it.