SudoCue 3.0.0.3: Solver Log Misclassification(s)

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Lambda
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SudoCue 3.0.0.3: Solver Log Misclassification(s)

Post by Lambda »

Starting with the following puzzle (generated in Simple Sudoku):

Code: Select all

1 . .|. 8 .|. 2 .
9 . .|3 2 .|. . 6
. . .|9 . .|5 . .
-----+-----+-----
. . .|. . 4|. 1 .
5 9 .|. . .|. 3 4
. 2 .|6 . .|. . .
-----+-----+-----
. . 5|. . 9|. . .
2 . .|. 4 8|. . 3
. 8 .|. 3 .|. . 7
And following the solving steps directly as listed in the "Solver Log", I get the following as the first 23 steps:

01: Digit 2 is a hidden single for R3C3 in multiple houses
02: Digit 3 is a hidden single for R1C7 in multiple houses
03: Digit 3 is a hidden single for R6C6 in multiple houses
04: Digit 4 is a hidden single for R1C4 in multiple houses
05: Digit 9 is both a naked and a hidden single for R1C9
06: Hidden single in column 3 for digit 3
07: Column 2 only has candidates for digit 1 in box 7
08: Column 5 only has candidates for digit 5 in box 5
09: Column 4 only has candidates for digit 5 in box 8
10: Column 8 only has candidates for digit 6 in box 9
11: Column 9 only has candidates for digit 5 in box 6
12: Naked Triple in column 5 for digits (1,6,7)
13: Hidden single in row 6 for digit 1
14: Digit 4 is a hidden single for R6C1 in multiple houses
15: Naked single for digit 6 in R9C1
16: Hidden single in box 8 for digit 6
17: Digit 6 is a hidden single for R8C8 in multiple houses
18: Digit 5 is a hidden single for R9C8 in multiple houses
19: Digit 5 is a hidden single for R8C4 in multiple houses
20: Hidden single in box 8 for digit 7
21: Hidden single in column 8 for digit 9
22: Digit 9 is a hidden single for R4C5 in multiple houses
23: Column 5 has one empty cell for the final digit 5

Step 23 is not a Full House - Column (4 points). Cells, R3C5 & R5C5 still have candidates 1, 7 in them. It is a Mixed Single (C5, B5 + Naked Single).

If I paste the Filled in puzzle as it stands after step 20:

Code: Select all

1 . .|4 8 .|3 2 9
9 . .|3 2 .|. . 6
. . 2|9 . .|5 . .
-----+-----+-----
. . 3|. . 4|. 1 .
5 9 .|. . .|. 3 4
4 2 1|6 . 3|. . .
-----+-----+-----
. . 5|7 6 9|. . .
2 . .|5 4 8|. 6 3
6 8 .|. 3 .|. 5 7
The step that fills in R6C5, correctly labels it as a Mixed Single (step 3):

01: Hidden single in column 8 for digit 9
02: Digit 9 is a hidden single for R4C5 in multiple houses
03: Digit 5 is a hidden single for R6C5 in multiple houses

Or if I paste in the puzzle with Pencil Marks from step 20:

Code: Select all

.------------------.------------------.------------------.
| 1     567   67   | 4     8     567  | 3     2     9    |
| 9     457   478  | 3     2     157  | 1478  478   6    |
| 378   3467  2    | 9     17    167  | 5     478   18   |
:------------------+------------------+------------------:
| 78    67    3    | 28    59    4    | 26789 1     258  |
| 5     9     678  | 128   17    127  | 2678  3     4    |
| 4     2     1    | 6     59    3    | 789   789   58   |
:------------------+------------------+------------------:
| 3     134   5    | 7     6     9    | 1248  48    128  |
| 2     17    79   | 5     4     8    | 19    6     3    |
| 6     8     49   | 12    3     12   | 1249  5     7    |
'------------------'------------------'------------------'
The system correctly classifies it (again in step 3):

01: Hidden single in column 8 for digit 9
02: Digit 9 is a hidden single for R4C5 in multiple houses
03: Digit 5 is both a naked and a hidden single for R6C5
Ruud
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Post by Ruud »

Hi, welcome to the forum.

This error is the result of an optimization I built into the program. In step 12, a naked triple (1,6,7) is isolated in column 5. To prevent the program from searching this column again for subsets, internally it is split into 2 sub-columns, a 3-cell part with digits (1,6,7) and a 2-cell part with digits (5,9). After the single 9 in r4c5, there is only 1 cell left in the 2-cell part and a full house is reported.

When you restart from the filled position, the program does not need the naked triple and the cells are not isolated.

I will correct this in the next release. Thanks for reporting it.

Ruud
Lambda
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Joined: Sat Aug 04, 2007 4:59 pm

Post by Lambda »

Ruud wrote:This error is the result of an optimization I built into the program.

I will correct this in the next release. Thanks for reporting it.
I'm amazed at your quick response and support for your software. You're doing a great job.

Between 2.2 and 3.0, you also seem to have optimized away the difference between Locked Candidates 1 and Locked Candidates 2. You never get Locked Candidates 2 any more, only Locked Candidates 1 unless you disable Locked Candidates 1 from the solving techniques list.

If I run classify (File -> Classify) on top95 using the 2.2 solver, it will use L1 on 86 of the puzzles, and L2 on 54 of the puzzles. If I run classify (Collection -> Rate) on top95 using the 3.0 solver, it will use L1 on 90 of the puzzles, and L2 on 0 of the puzzles.

For example, the following in 2.2's Solver's Used Techniques uses Locked Candidates 1 four times, and Locked Candidates 2 one time.

Code: Select all

. 1 6|. . 2|. 4 .
. 5 .|3 . .|. 7 6
. 3 .|. 5 .|. . .
-----+-----+-----
. 7 1|5 . .|. . .
. . .|. 2 .|. . .
. . .|. . 8|7 5 .
-----+-----+-----
. . .|. 4 .|. 3 .
4 6 .|. . 5|. 2 .
. 2 .|7 . .|9 8 .
Solving steps 13, 14, and 15 are L1, L1, and L2 respectively:

13: Box 1 only has candidates for digit 4 in column 3
14: Box 8 only has candidates for digit 8 in row 8
15: Column 4 only has candidates for Digit 1 in box 5

Using 3.0's solver, steps 13, 14, and 15 are L1, L1, L1 respectively:

13: Row 7 only has candidates for digit 8 in box 7
14: Column 2 only has candidates for digit 4 in box 4
15: Column 4 only has candidates for digit 1 in box 5

If I disable using L1, I get the following (all L2's, obviously):

13: Box 8 only has candidates for Digit 8 in row 8
14: Box 1 only has candidates for Digit 4 in column 3
15: Column 4 only has candidates for Digit 1 in box 5
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