SudoCue Users

Posted: **Sun Oct 15, 2006 5:40 pm**

This puzzle has two finned swordfish, according to Sudoku Cue.
I see the first one but the second, which follows the first I cannot detect,
even when I am looking at the outputted hint.

Is the second one truly a swordfish at all?

Code: Select all

...839...
..4.5.7..
8.12.73.5
35..1..72
.........
..2.7.4..
1...2...3
.........
.75.8.29.

Here is the key markup: The +6 is the fin? The -6 is the elimination.
I don't get it. <sigh>

Code: Select all

.------------------.------------------.------------------.
| 5     6     7    | 8     3     9    | 1     2     4    |
| 2     3     4    |*16    5    *16   | 7     8     9    |
| 8     9     1    | 2     4     7    | 3     6     5    |
&#58;------------------+------------------+------------------&#58;
| 3     5     68   | 469   1     468  | 69    7     2    |
| 7     4     68   | 3569  69    2    | 59    135   168  |
| 9     1     2    |*356   7    *3568 | 4     35   *68   |
&#58;------------------+------------------+------------------&#58;
| 1     8     9    | 7     2    *456  | 5+6   45    3    |
| 46    2     3    | 14569 69    1456 | 8     145   7    |
| 46    7     5    | 1346  8     1346 | 2     9     1-6  |
'------------------'------------------'------------------'

Posted: **Sun Oct 15, 2006 8:39 pm**

The second swordfish is a "sashimi" swordfish. It is not complete, but you can still do the same eliminations. Because it is hard to locate, people sometimes mark all the cells that belong to the swordfish pattern, even when there is no candidate in that cell:

Code: Select all

.------------------.------------------.------------------. 
| 5     6     7    | 8     3     9    | 1     2     4    | 
| 2     3     4    |*16    5    *16   | 7     8    *9    | 
| 8     9     1    | 2     4     7    | 3     6     5    | 
&#58;------------------+------------------+------------------&#58; 
| 3     5     68   | 469   1     468  | 69    7     2    | 
| 7     4     68   | 3569  69    2    | 59    135   168  | 
| 9     1     2    |*356   7    *3568 | 4     35   *68   | 
&#58;------------------+------------------+------------------&#58; 
| 1     8     9    |*7     2    *456  | 5+6   45   *3    | 
| 46    2     3    | 14569 69    1456 | 8     145   7    | 
| 46    7     5    | 1346  8     1346 | 2     9     1-6  | 
'------------------'------------------'------------------'

the +6 is the fin indeed.

Posted: **Fri Jan 26, 2007 8:57 pm**

Great explanation Ruud. Very hard for me to spot, I'll use your advice and mark the whole pattern. Thanks.

SudoCue Users

Finned swordfish.

Finned swordfish.