Country Codes
Wikipedia is my favorite source for all kinds of information and they did a nice job on the country codes. Unfortunately, the page goes by the name ISO 3166-1 so it's not as easy as it could be to find.
Link
Link
Shortest Sudoku solver in Python
Mark Byer's site has some more Sudoku solvers here's a short one in Python that's only 178 bytes long:def r(a):i=a.find('0');~i or exit(a);[m
in[(i-j)%9*(i/9^j/9)*(i/27^j/27|i%9/3^j%9/3)or a[j]for
j in range(81)]or r(a[:i]+m+a[i+1:])for m in'%d'%5**18]
from sys import*;r(argv[1]) On the site is also shown a longer Perl version at 185 bytes:
use integer;sub R{for$i(grep!$A[$_],@x=0..80){%t=map{$_/27-$i/27|$_%9/3-$i%9/3&&$_
/9-$i/9&&($_-$i)%9?0:$A[$_]=>1}@x;R($A[$i]=$_)for grep!$t{$_},1..9;return$A[$i]=0}
die@A}@A=split//,<>;R I think the Python version is slightly easier to understand, although they are both quite cryptic.
I'm not sure why I find these programs fascinating. I think it reminds me that any program can be written in such a way that it's cryptic, even in Python. In addition, the code is small enough that you should be able to figure out how it works, and may learn something the process.
Related is:
how to sol…
in[(i-j)%9*(i/9^j/9)*(i/27^j/27|i%9/3^j%9/3)or a[j]for
j in range(81)]or r(a[:i]+m+a[i+1:])for m in'%d'%5**18]
from sys import*;r(argv[1]) On the site is also shown a longer Perl version at 185 bytes:
use integer;sub R{for$i(grep!$A[$_],@x=0..80){%t=map{$_/27-$i/27|$_%9/3-$i%9/3&&amp;amp;$_
/9-$i/9&&($_-$i)%9?0:$A[$_]=>1}@x;R($A[$i]=$_)for grep!$t{$_},1..9;return$A[$i]=0}
die@A}@A=split//,<>;R I think the Python version is slightly easier to understand, although they are both quite cryptic.
I'm not sure why I find these programs fascinating. I think it reminds me that any program can be written in such a way that it's cryptic, even in Python. In addition, the code is small enough that you should be able to figure out how it works, and may learn something the process.
Related is:
how to sol…
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