The New Sudoku Players' Forum

[ArkieTech]

Here is another puzzle from Beldon vol 9 number 104 Pappacom verifies it as v Hard.

Code: Select all

Starting Puzzle:

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

*--------------------------------------------------------------------------------*
|  1       239     4       |  2379    5       2379    |  6       8       2479    |
|  3589    7       58      |  239     6       4       |  2       259     1       |
|  459     29      6       |  8       127     1279    |  3       24579   24579   |
|--------------------------+--------------------------+--------------------------|
|  35678   368     9       |  23567   2478    23578   |  248     1       23458   |
|  358     1       2       |  359     48      3589    |  7       6       3458    |
|  35678   4       578     |  123567  1278    123578  |  9       25      2358    |
|--------------------------+--------------------------+--------------------------|
|  4789    89      3       |  127     1278    6       |  5       2479    24789   |
|  2       68      78      |  4       9       1578    |  18      3       78      |
|  4789    5       1       |  27      3       278     |  248     6       24789   |
*--------------------------------------------------------------------------------*


I did not get far before getting stuck

Code: Select all

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

*--------------------------------------------------------------------------------*
|  1       239     4       |  2379    5       2379    |  6       8       79      |
|  3589    7       58      |  39      6       4       |  2       59      1       |
|  59      29      6       |  8       127     1279    |  3       4579    4579    |
|--------------------------+--------------------------+--------------------------|
|  35678   38      9       |  23567   2478    2378    |  48      1       23458   |
|  358     1       2       |  359     48      389     |  7       6       3458    |
|  35678   4       578     |  123567  1278    12378   |  9       25      2358    |
|--------------------------+--------------------------+--------------------------|
|  4789    89      3       |  127     1278    6       |  5       2479    24789   |
|  2       6       78      |  4       9       5       |  1       3       78      |
|  4789    5       1       |  27      3       278     |  48      2479    6       |
*--------------------------------------------------------------------------------*

help?


dan

[daj95376]

Dan, your original puzzle has 51 solutions. Did you make a mistake transcribing it? In any event, you wrestled it down to where only one solution remains. Colors, Multi-Colors, and an XY-Chain will solve it. Wait and see if someone offers something more user-friendly. That's very likely!

[udosuk]

I think the xy-chain daj mentioned could be this one:

Code: Select all

 *-----------------------------------------------------------------------------*
 | 1       239     4       | 2379    5       2379    | 6       8      *79      |
 | 3589    7      *58      | 39      6       4       | 2      *59      1       |
 | 59      29      6       | 8       127     1279    | 3       4579    4579    |
 |-------------------------+-------------------------+-------------------------|
 | 35678   38      9       | 23567   2478    2378    | 48      1       23458   |
 | 358     1       2       | 359     48      389     | 7       6       3458    |
 | 35678   4       578     | 123567  1278    12378   | 9       25      2358    |
 |-------------------------+-------------------------+-------------------------|
 | 4789    89      3       | 127     1278    6       | 5       2479    24789   |
 | 2       6      -78      | 4       9       5       | 1       3      *78      |
 | 4789    5       1       | 27      3       278     | 48      2479    6       |
 *-----------------------------------------------------------------------------*

r8c3 cannot be 8, otherwise we'll have two 9s in box 3.

After this move only singles are needed...

I hope others can post more elegant moves...

BTW, like daj said your original puzzle has 51 solutions! How did you determine r8c2 as 6 instead of 8?

[ArkieTech]

Dan, your original puzzle has 51 solutions. Did you make a mistake transcribing it?

Yes, I boo-booed here is the original puzzle:

Code: Select all

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


*--------------------------------------------------------------------------------*
|  1       239     4       |  2379    5       2379    |  6       8       2479    |
|  3589    7       58      |  239     6       4       |  2       259     1       |
|  459     29      6       |  8       127     1279    |  3       24579   24579   |
|--------------------------+--------------------------+--------------------------|
|  35678   368     9       |  23567   2478    23578   |  248     1       23458   |
|  358     1       2       |  359     48      3589    |  7       6       3458    |
|  35678   4       578     |  123567  1278    123578  |  9       25      2358    |
|--------------------------+--------------------------+--------------------------|
|  4789    89      3       |  127     1278    6       |  5       2479    24789   |
|  2       68      78      |  4       9       1578    |  18      3       78      |
|  4789    5       1       |  27      3       278     |  248     2479    6       |
*--------------------------------------------------------------------------------*


[ArkieTech]

r8c3 cannot be 8, otherwise we'll have two 9s in box 3.

Wow! finding this xy chain quickly yields the solution. I have so much to learn.

Thanks

dan

[daj95376]

udosuk: Yes, that was the XY-Chain my solver found. Except, the conclusion was [r8c8]<>7. This ends up matching your results.

Nice catch on not needing to do all of the coloring steps for <3> and <8>! I still haven't gotten into the habit of checking to see if steps can be skipped.

[tarek]

There is also an ALS xz targeting an 8 which cracks it.....

too many fish targeting 8s though "CRAZY 8"

tarek

[daj95376]

Yes tarek, a crazy set of seven eliminations on <8>.

Code: Select all

# Kraken Jellyfish with two oddly arranged (to me) fin cells
# Jellyfish [R2568c1359]                                    => all eliminations
# Fin cells [r56c6] => Jellyfish degenerates into Swordfish => all eliminations
 *-----------------------------------------------------------------------------*
 | 1       239     4       | 2379    5       2379    | 6       8       79      |
 |*3589    7      *58      | 39      6       4       | 2       59      1       |
 | 59      29      6       | 8       127     1279    | 3       4579    4579    |
 |-------------------------+-------------------------+-------------------------|
 | 3567-8  38      9       | 2567    247-8   237-8   | 48      1       2345-8  |
 |*358     1       2       | 359    *48     #389     | 7       6      *3458    |
 |*35678   4      *578     | 123567 *1278   #12378   | 9       25     *2358    |
 |-------------------------+-------------------------+-------------------------|
 | 479-8   89      3       | 127     1278    6       | 5       2479    2479-8  |
 | 2       6      *78      | 4       9       5       | 1       3      *78      |
 | 479-8   5       1       | 27      3       278     | 48      2479    6       |
 *-----------------------------------------------------------------------------*


[ronk]

Yes tarek, a crazy set of seven eliminations on <8>.

# Kraken Jellyfish with two oddly arranged (to me) fin cells
# Jellyfish [R2568c1359] => all eliminations
# Fin cells [r56c6] => Jellyfish degenerates into Swordfish => all eliminations

It may also be viewed as a franken jellyfish ... aka 4x4 constraint sets. The candidates in r2568 are covered by c139b5. All other candidates in c139b5 may be excluded.

Code: Select all

 .  .  . |  .  .  . |  .  .  .
*8  . *8 |  .  .  . |  .  .  .
 .  .  . |  .  .  . |  .  .  .
---------+----------+----------
-8  8  . |  . -8 -8 |  8  . -8
*8  .  . |  . *8 *8 |  .  . *8
*8  . *8 |  . *8 *8 |  .  . *8
---------+----------+----------
-8  8  . |  .  8  . |  .  . -8
 .  . *8 |  .  .  . |  .  . *8
-8  .  . |  .  .  8 |  8  .  .
 (unfinned) franken jellyfish r2568\c139b5

Or a franken swordfish ... aka 3x3 constraint sets. All the candidates in c27b8 are covered by r479. Therefore all other candidates in r479 may be excluded.

Code: Select all

 .  .  . |  .  .  . |  .  .  .
 8  .  8 |  .  .  . |  .  .  .
 .  .  . |  .  .  . |  .  .  .
---------+----------+----------
-8 *8  . |  . -8 -8 | *8  . -8
 8  .  . |  .  8  8 |  .  .  8
 8  .  8 |  .  8  8 |  .  .  8
---------+----------+----------
-8 *8  . |  . *8  . |  .  . -8
 .  .  8 |  .  .  . |  .  .  8
-8  .  . |  .  . *8 | *8  .  .
 (unfinned) franken swordfish c27b8\r479

Or a continuous x-cycle of length 6.

-8-r4c2=8=r7c2-8-r7c5=8=r9c6-8-r9c7=8=r4c7-8-r4c2-

[Len]

Low tech solution: from the code of Wed Nov 22, 2006 7:41 pm 7 does not work in r1c9; 9 breaks the puzzle.

[StrmCkr]

Yes, I boo-booed here is the original puzzle

i still get three solutions? from that retyping..

[udosuk]

i still get three solutions? from that retyping..

That just shows that your solving methods were flawed...

This puzzle:

Code: Select all

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

Absolutely has 1 and only 1 unique solution:

Code: Select all

124|753|689
378|964|251
596|812|347
---+---+---
639|527|814
812|349|765
745|681|923
---+---+---
483|176|592
267|495|138
951|238|476

Show us your other 2 solutions and let us show you where you went wrong...

[JPF]

i still get three solutions? from that retyping..

An easy way to get 3 solutions is to remove (forget ?) r4c3 = 9 ...

JPF

[StrmCkr]

wasnt trying my solving methods. it only works on puzzles with 1 solution :P

i typed it into a solution checker and it consitatly produced 3 solutions. every time i retyped it in..

so i guess is missed something and

thanks jpf!!

yeah thats what i did i missed

r4c3 = 9 thanks!!


on a side note

there is lots of options to choose from on this puzzle for my methods.

i just spot a conjugated Pair in quad 4 execut yield chain type 1 on quad 4 solves

D2 =3

look for other conjugated pair or Chian
find i find another one in Quad 8 execute type 1 yeild chain,

Solves J4 = 2

puzzle solved, rest as singles.

i just find it easier to spot chained events in specified areas 1 row/ 1 quad/ 1 column

Rather then look for some massive overlaid pattern.

strmckr

[ronk]

i just spot a conjugated Pair in quad 6 execut yield chain type 1 on quad 4 solves
D2 =3

look for other conjugated pair or Chian
find i find another one in Quad 8 execute type 1 yeild chain,

Solves J4 = 2

puzzle solved, rest as singles.

Letting alone the "type 1", do you seriously think anyone looking for help will know what a "yield chain" is?