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| JPF
| Joined: 05 Dec 2005 | Posts: 29 | : | Location: Paris | Items |
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Posted: Sat Feb 18, 2006 12:45 am Post subject: The minimum easiest puzzles |
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I'm interested in the easy puzzles.
Obviously, easiest are the full grids ! (81 clues, 0 holes).
Now, let's agree that the easiest puzzles are those which can been solved by only using the F constraint (Forced cell : only one value possible).
Let's call such puzzles : F-puzzles
Question : what is the minimum F-puzzle (with the minimum number of clues)
My own record is 22 :
Code: |
1 . .|. . 4|. . .|
. 2 .|. . .|. . 8|
. 8 4|. 5 .|1 6 .|
-----+-----+-----
. . .|. . .|8 . .|
7 . 5|9 . .|. . 3|
. . .|1 6 .|. . .|
-----+-----+-----
. 9 .|. . 5|4 . .|
. 4 .|. . .|6 . .|
. . .|. . 2|. . .|
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My Generator is rather slow and I'm sure that one can do much better.
BTW, I didn't find any F-puzzle in the Gordon's 17-clues list.
http://www.csse.uwa.edu.au/~gordon/sudokumin.php
JPF |
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| Ruud Site Admin
| Joined: 17 Sep 2005 | Posts: 708 | : | Location: Netherlands | Items |
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Posted: Sat Feb 18, 2006 3:46 am Post subject: |
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JPF wrote: | Now, let's agree that the easiest puzzles are those which can been solved by only using the F constraint (Forced cell : only one value possible). |
Many would not agree with you on this premise. I certainly don't. The N-constraint is easier to solve than the F-constraint, which requires pencilmarks.
JPF wrote: | BTW, I didn't find any F-puzzle in the Gordon's 17-clues list. |
Maybe not, but there are several that only require N-constraints.
Ruud. _________________ Meet me at sudocue.net |
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| Finlip
| Joined: 03 Aug 2006 | Posts: 2 | : | Location: Kathmandu, Nepal | Items |
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Posted: Fri Aug 04, 2006 1:33 pm Post subject: |
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If you have a computer program with automatically generated pencil marks, forced cells are easiest. Yes it is more difficult for the naked eye to spot than are a few others. |
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| anttiahola
| Joined: 29 Jul 2006 | Posts: 14 | : | | Items |
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Posted: Fri Aug 25, 2006 7:22 pm Post subject: |
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Hmm, they seem to be quite rare. My generator had to make 100 000 random boards in order to output these two:
Code: |
-----------------
initialValues: 21
6.8|..7|.5.
...|9..|.6.
..5|..4|...
---+---+---
4..|...|...
.9.|...|...
...|.7.|..3
---+---+---
.1.|...|.39
...|.8.|..1
...|.56|7.2
-----------------
initialValues: 21
6..|9.3|...
..9|8..|...
.7.|...|45.
---+---+---
12.|.6.|...
.5.|...|.7.
..6|3..|...
---+---+---
...|69.|...
..8|...|.4.
2..|.1.|...
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