## It's raining. Get the "Umbrella" (puzzle solved).

Post puzzles for others to solve here.

### It's raining. Get the "Umbrella" (puzzle solved).

Hi,
The original design has numbers where the four "+" signs are. The numbers were placed to make the umbrella pattern more suggestive even though after removing the "+"'s the puzzle still have a unique solution.

I am enclosing the text representation of the puzzle with no "+" signs:
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` *-----------* |..4|2.6|...| |.61|...|34.| |...|...|.1.| |---+---+---| |...|1..|...| |...|.4.|..5| |...|9.3|8.2| |---+---+---| |6.2|...|..9| |83.|...|.7.| |...|...|...| *-----------*`

And just in case, the row-wise string representation (enlarge your browser's window to make sure that the string fits).
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`004206000061000340000000010000100000000040005000903802602000009830000070000000000 `

Enjoy,

Oscar

P.S. The original (easier) puzzle is here.
OscarSeurat

Posts: 8
Joined: 09 September 2018

### Re: It's raining. Get the "Umbrella" (puzzle solved).

Hi Oscar! That's better, but still too easy. Only basic steps needed, though quite a few of them. Can you make them harder still?

In the mean time, let's make a new type of challenge out of this one:

Only singles allowed both before and after the decisive step(s)!

Seems pretty hard to bypass all the basic steps of this puzzle with just one advanced move.
Code: Select all
`   *             |    |               |    |    *        *        |=()=|    /  _  \    |=()=|               *            *    |    |   |-=( )=-|   |    |      *     *                     \  ¯  /                   *    `
SpAce

Posts: 1285
Joined: 22 May 2017

### Re: It's raining. Get the "Umbrella" (puzzle solved).

One way to make more difficult puzzles that will please the expert solvers visiting this thread is:

- put the oneline puzzle (pattern) into a text file (e.g. umbrella.txt for the original puzzle).
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`..4216....61...34....7...1....1....4....4...5...9.38.26.2....8983.....7..........`

- use gsf.exe to generate new puzzles from this pattern.
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`gsf.exe -n100 -gto{-3+3}p -euniq()*(1==minimal) -f%v -opuzzles.txt < umbrella.txt`

This creates 100 new puzzles in puzzles.txt.

- rate the new puzzles with SudokuExplainer.
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`java.exe -Xrs -Xmx500m -cp SudokuExplainer.jar diuf.sudoku.test.serate --format="%g ED=%r/%p/%d" --input=puzzles.txt --output=ratedpuzzles.txt`

Note: SudokuExplainer requires java to be installed.

Any puzzles in ratedpuzzles.txt with ratings 6.X-7.X will be 'tough' enough to interest the solvers here.

gsf.exe (size: 519,680 bytes): http://forum.enjoysudoku.com/gsf-s-sudoku-solver-t30415-15.html#p231359

Here's one umbrella puzzle that is rated ED=7.1/1.2/1.2:
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`..6729....34...62....6...8....1....7....4...8...5.34.19.5....7427.....5..........`
1to9only

Posts: 823
Joined: 04 April 2018

### Re: It's raining. Get the "Umbrella" (puzzle solved).

1to9only wrote:One way to make more difficult puzzles that will please the expert solvers visiting this thread is:

[snip]

- use gsf.exe to generate new puzzles from this pattern.

Great idea!

enxio27

Posts: 484
Joined: 13 November 2007

### Re: It's raining. Get the "Umbrella" (puzzle solved).

1to9only wrote:One way to make more difficult puzzles that will please the expert solvers visiting this thread is...
Here's one umbrella puzzle that is rated ED=7.1/1.2/1.2

Great idea, like enxio27 said! I guess we could start with that (pretty easy) example:

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`.--------------------.----------------.----------------.| 58     58     6    | 7   2     9    | 1       4    3 || 7      3      4    | 8   15    15   | 6       2    9 || 1      29     29   | 6   3     4    | 7       8    5 |:--------------------+----------------+----------------:| 34568  45689  89   | 1   689   268  | 25      369  7 || 356    1569   179  | 29  4     267  | 25      369  8 || 68     2689   2789 | 5   6789  3    | 4       69   1 |:--------------------+----------------+----------------:| 9      18     5    |b23  168   1268 |a3(8)    7    4 || 2      7      138  | 4   189   18   | 389     5    6 || 46     46     38   |c39  57    57   |d3(9)-8  1    2 |'--------------------'----------------'----------------'`

(8=3)r7c7 - r7c4 = (3-9)r9c4 = (9)r9c7 => -8 r9c7; stte

Btw, I guess that's some kind of a wing, but could someone tell me what kind exactly? I get confused with the zillion letter designations. The standard solution here would be the W-Wing right next to this, but this is obviously one of those other letters (if anything). (Also, I guess being solvable by a simple W-Wing makes this still a bit too easy as well.)
Code: Select all
`   *             |    |               |    |    *        *        |=()=|    /  _  \    |=()=|               *            *    |    |   |-=( )=-|   |    |      *     *                     \  ¯  /                   *    `
SpAce

Posts: 1285
Joined: 22 May 2017