The New Sudoku Players' Forum

[Para]

It was speeded up by checking if two landcells can be found that are definitely separated by a water line - which was actually quite easy to program.
The second puzzle was solved in 3 hrs. Checking that the solution is unique was at least ready when I looked the next morning.

I'm not very surprised that one takes long because it employs a few observations at the start that i assume are hard to program. As they are all the same number and not connectable with one area of 8 cells, every clue needs at least 2 sections. Then the second observation is that because all numbers are seperated by at least 2 cells, except for one pair so all size 7 islands would have to touch one of those cells.
Those were the 2 ideas I set at the start after placing the first 2 clues in the top left corner. As long as I would make sure all 8s were spread enough and were never 1 or fewer cells apart, I would be sure the logic I used i the beginning would hold.

[dyitto]

Another one:

Code: Select all

3;.;.;.;7;.;.;.;.
.;3;.;.;.;.;.;.;4
.;4;.;.;.;2;.;1;.
.;.;.;2;.;.;.;.;.
.;.;7;.;.;4;.;.;.
.;.;.;.;5;.;.;1;.
.;.;.;.;.;.;3;.;.
.;2;.;.;.;.;.;3;.
2;.;4;.;3;2;.;.;.


I'll put my program online as soon as the UI is a bit more decent.

[dyitto]

I should also try to write a short program to verify uniqueness using brute force. Should not be too hard I suppose?

You can check my solver here:
http://www.scrybqj.com/downloads/island/

[dyitto]

Another puzzle:

Code: Select all

.;.;.;.;.;2;.;.;.
7;.;.;.;7;.;.;.;.
.;.;.;.;.;.;5;.;.
.;.;.;5;.;.;.;.;.
.;6;.;.;.;3;.;.;5
.;.;.;.;.;.;.;.;.
.;.;.;.;8;.;.;.;.
.;2;.;3;.;7;.;.;.
.;2;.;.;.;.;.;4;.


[simon_blow_snow]

Another puzzle:

Code: Select all

3;.;.;.;7;.;.;.;.
.;3;.;.;.;.;.;.;4
.;4;.;.;.;2;.;1;.
.;.;.;2;.;.;.;.;.
.;.;7;.;.;4;.;.;.
.;.;.;.;5;.;.;1;.
.;.;.;.;.;.;3;.;.
.;2;.;.;.;.;.;3;.
2;.;4;.;3;2;.;.;.


It is a very nice medium-level puzzle!

Solution: Show

Code: Select all

3@@@7@@@@
#3######4
@4#@#2@1#
@#@2#@###
@@7#@4###
##@@5@#1#
#####@3@#
@2#@@##3#
2@4@32@@#

dyitto, when you run your solver program on the other five of Para's puzzles as well as stages 3 & 4 of Naoki's, don't forget to tell us how they go.

[dyitto]

Did you solve both of my 9x9 puzzles? If one starts with random numbers they probably tend to be medium-level.

As for the other puzzles, my program usually confirms unique solution, and run-times differ from few seconds to 20 minutes to few hours.

[simon_blow_snow]

Did you solve both of my 9x9 puzzles? If one starts with random numbers they probably tend to be medium-level.

As for the other puzzles, my program usually confirms unique solution, and run-times differ from few seconds to 20 minutes to few hours.

Oopsy, I totally did not realise you posting a 3rd puzzle (even though I quoted your 3rd puzzle instead of the 2nd puzzle above). I just solved your 1st & 2nd ones.

You can make it clearer by including a title on top of your puzzle text (e.g. dyitto #1, dyitto #2).

Will have a go at your 3rd puzzle later.