The New Sudoku Players' Forum

[pjb]

Interestingly, yzfwsf's "Dual Firework ER" above is exactly the same configuration as I posted as "Twin ERs" https://forum.enjoysudoku.com/twin-empty-rectangles-t39739.html. It can also be regarded as an endo-finned mutant swordfish apparently.

Phil

[pjb]

yzfwsf wrote:

Code: Select all

modifying the code to allow individual FW missing corners

Hi yzfwsf, I'm struggling to understand what you mean by the above, and it looks like something very worthwhile. Could you please go into some detail?

Thanks, Phil

[yzfwsf]

yzfwsf wrote:

Code: Select all

modifying the code to allow individual FW missing corners

Hi yzfwsf, I'm struggling to understand what you mean by the above, and it looks like something very worthwhile. Could you please go into some detail?

Thanks, Phil

Hi Phil:
I'm so sorry to find your reply so late.I mean following:

Code: Select all

.------------.-------------.-----------.
| 1   26   3 | 25  9   568 | 7  46  48 |
| 5   9    4 | 3   7   68  | 1  26  28 |
| 26  8    7 | 12  16  4   | 5  3   9  |
:------------+-------------+-----------:
| 9   5    6 | 4   3   2   | 8  1   7  |
| 8   4    2 | 7   5   1   | 3  9   6  |
| 3   7    1 | 6   8   9   | 2  45  45 |
:------------+-------------+-----------:
| 7   12   9 | 8   16  56  | 4  25  3  |
| 26  126  8 | 15  4   3   | 9  7   25 |
| 4   3    5 | 9   2   7   | 6  8   1  |
'------------'-------------'-----------'
Firework Quadruple: 16r8c2b7, 25r1c4b2 is firework => r8c2<>2

1 in column 2 only appear in box 7
2 in column 4 only appear in box2
6 in row 9 only appear in box 7
5 in row 1 only appear in box 2

[shye]

.
new deduction added to main post:

Code: Select all

+-------+-------+-------+
| 9 . . | . 3 7 | . 8 . |
| . 7 . | 1 . . | . . 9 |
| 5 . . | 2 . . | . . . |
+-------+-------+-------+
| . 6 . | . . 5 | . . 8 |
| 4 . . | . . . | . . 7 |
| . . . | . . . | 2 3 . |
+-------+-------+-------+
| 7 . 5 | . . . | . . . |
| . 2 . | . . 6 | . 9 . |
| 6 . 9 | . 4 . | 5 . 1 |
+-------+-------+-------+
Heartline Roll - shye
skfr 8.6
9...37.8..7.1....95..2......6...5..84.......7......23.7.5.......2...6.9.6.9.4.5.1

.------------------.----------------------.-------------------.
| 9    14    1246  |*x456    3      7     | 146    8    *25   |
| 238  7     23468 |  1      568    48    | 346    25    9    |
| 5    1348  13468 |  2      689    489   | 13467  1467  346  |
:------------------+----------------------+-------------------:
| 123  6     1237  |  3479   1279   5     | 149    14    8    |
| 4    59    1238  |  3689   12689  12389 | 169    156   7    |
| 18   59    178   | x46789  16789  1489  | 2      3    x46-5 |
:------------------+----------------------+-------------------:
| 7    1348  5     |  389    1289   12389 | 3468   246   2346 |
| 138  2     1348  |  3578   1578   6     | 3478   9     34   |
| 6    38    9     |  378    4      238   | 5      27    1    |
'------------------'----------------------'-------------------'

dual firework l-wing

fireworks on 4&6 in r6c4b5
5r1c9 = (5-4|6)r1c4 = 46r6c49
-5r6c9 stte

this one is special for how few truths it has, only five! i previously thought fw triples would be the most simple application but even those are made up of 6 truths. granted, this doesnt seem like it will always be easy to spot unlike the triples
its also a new rank1 deduction (hooray!) which ive been hoping to find more useful applications of

XSudo Input: Show

5 Truths = {5R1 46R6 46C4}
6 Links = {5c9 16n4 6n9 46b5}

[yzfwsf]

.
new deduction added to main post:

Code: Select all

+-------+-------+-------+
| 9 . . | . 3 7 | . 8 . |
| . 7 . | 1 . . | . . 9 |
| 5 . . | 2 . . | . . . |
+-------+-------+-------+
| . 6 . | . . 5 | . . 8 |
| 4 . . | . . . | . . 7 |
| . . . | . . . | 2 3 . |
+-------+-------+-------+
| 7 . 5 | . . . | . . . |
| . 2 . | . . 6 | . 9 . |
| 6 . 9 | . 4 . | 5 . 1 |
+-------+-------+-------+
Heartline Roll - shye
skfr 8.6
9...37.8..7.1....95..2......6...5..84.......7......23.7.5.......2...6.9.6.9.4.5.1

.------------------.----------------------.-------------------.
| 9    14    1246  |*x456    3      7     | 146    8    *25   |
| 238  7     23468 |  1      568    48    | 346    25    9    |
| 5    1348  13468 |  2      689    489   | 13467  1467  346  |
:------------------+----------------------+-------------------:
| 123  6     1237  |  3479   1279   5     | 149    14    8    |
| 4    59    1238  |  3689   12689  12389 | 169    156   7    |
| 18   59    178   | x46789  16789  1489  | 2      3    x46-5 |
:------------------+----------------------+-------------------:
| 7    1348  5     |  389    1289   12389 | 3468   246   2346 |
| 138  2     1348  |  3578   1578   6     | 3478   9     34   |
| 6    38    9     |  378    4      238   | 5      27    1    |
'------------------'----------------------'-------------------'

dual firework l-wing

fireworks on 4&6 in r6c4b5
5r1c9 = (5-4|6)r1c4 = 46r6c49
-5r6c9 stte

this one is special for how few truths it has, only five! i previously thought fw triples would be the most simple application but even those are made up of 6 truths. granted, this doesnt seem like it will always be easy to spot unlike the triples
its also a new rank1 deduction (hooray!) which ive been hoping to find more useful applications of

XSudo Input: Show

5 Truths = {5R1 46R6 46C4}
6 Links = {5c9 16n4 6n9 46b5}

same below?
g-Whip[5]: Supposing 5r6c9 would causes 6 to disappear in Box 2 => r6c9<>5
5r6c9 - 5r1(c9=c4) - 4c4(r1=r46) - 4r6(c6=c4) - 6r6(c4=c5) - 6b2(p8=.)

[shye]

same below?
g-Whip[5]: Supposing 5r6c9 would causes 6 to disappear in Box 2 => r6c9<>5
5r6c9 - 5r1(c9=c4) - 4c4(r1=r46) - 4r6(c6=c4) - 6r6(c4=c5) - 6b2(p8=.)

so im not too sure about how these work but looking at which components are involved it does seem very similar
is the method here placing digits until contradiction, then winding back? if so i would probably think of it as:

suppose 5r6c9
4 and 6 in b5 locked to r6
46 hidden pair in c4
there is nowhere for 5 in r1

[StrmCkr]

whips are memory chains they retain some data as they progress to perform contradiction eliminations based on a sector lacking a placement.