o, safe pawns... creative solution for Pawn Brotherhood by veky - python coding challenges

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o, safe pawns... solution in Creative category for Pawn Brotherhood by veky

o,safe_pawns=lambda l,d=-1:chr(ord(l)+d),lambda P:sum(bool({o(f)+o(r),o(f,1)+o(r)}&P)for f,r in P)

July 30, 2014

Comments:

Peter.White on April 2, 2015, 8:43 p.m.
How do you not get headaches when writing something like this? I get them just from reading it. ;)

veky on April 3, 2015, 5:02 a.m.
Well, I get headaches from reading your solutions, so we're even. :-P Let me tell you a secret: I don't really write things like this directly. This probably went through a phase such as <pre class='brush: python'>def safe_pawns(pawns): shift = lambda coord, diff: chr(ord(coord) + diff) count = 0 for file, row in pawns: under, left, right = shift(row, -1), shift(file, -1), shift(file, 1) if {left + under, right + under} & pawns: count += 1 return count </pre> You can probably see it's the same algorithm, just written vertically instead of horizontally. :-) And one more thing: golfing is not the same as factoring (extracting repeated functionality into a separate step, for example `shift` function above). Yes, factoring usually produces shorter code, but many times factored code is even longer. I like factored code more for two reasons: readability (giving sensible names to things always helps) and maintainability (you're confident only one or two places need to change, for every change of requirements).

fd2fd4ad on Sept. 18, 2015, 11:31 a.m.
It's seems like cool, but it's unreadable %)

veky on Sept. 18, 2015, 11:50 a.m.
Cool is irrelevant. For readability, does the <a href="http://www.checkio.org/mission/pawn-brotherhood/publications/veky/python-3/o-safe-pawns/share/721e23752f6be3fbc08703ff7483ac41/#comment-28028">above comment</a> help?

xiaozhan on Nov. 17, 2015, 8:46 a.m.
How about <a href="http://www.checkio.org/mission/pawn-brotherhood/publications/xiaozhan/python-3/int-with-base18/?ordering=newest">this</a>!

veky on Nov. 17, 2015, 6:32 p.m.
Cool idea. ;-)

xiaozhan on Nov. 17, 2015, 8:53 a.m.
Congratulations,You get level 20!

veky on Nov. 17, 2015, 6:19 p.m.
Thanks, you're the first to congratulate me. :-) Here is a nice trivia about that number: do you know (without looking) what is PEP #20 and why? :-)

xiaozhan on Nov. 18, 2015, 1:55 a.m.
Actually, I don't Know about what is PEP #20 and why?But I find I know it's content when I looking it, I read it in a book, and see it's content by 'import this'. BTW:Did you mean my solution is not explicit? especially the number 18？

veky on Nov. 18, 2015, 5 a.m.
No, that trivia is not explicitly[:-P] related to your solution. It's related to your congratulations. :-) So, import this and count the aphorisms. Notice that one is missing. ;-)

xiaozhan on Nov. 18, 2015, 6:32 a.m.
Did you mean there used to be 20 aphorisms?Now there is only 19, and I guess the last one used to be "Congratulations". BTW:The top level is 20, it comes from there?

veky on Nov. 18, 2015, 7:49 a.m.
You're reading too much into it. Go, look at official text of <a href="https://www.python.org/dev/peps/pep-0020/">PEP#20</a> (Abstract), and everything will be clear (hopefully). ;-) About top level, that's something you have to ask the admins about. I think it would be very cool if that was the answer. Too cool to be true, in fact. :-D

Sukonnik-Illia on Dec. 24, 2015, 11:33 p.m.
My nightmare about legacy code :)

veky on Dec. 25, 2015, 7:24 a.m.
Seriously? One line? :-) No matter how obfuscated it is, I'm sure you can figure it out in a shorter time than a 50line behemoth with 20 comments that are unsynced with the code. :-P And this one even comes with a <a href="http://www.checkio.org/mission/pawn-brotherhood/publications/veky/python-3/o-safe-pawns/share/721e23752f6be3fbc08703ff7483ac41/#comment-28028">key</a> included. ;-)

charli-polo on Oct. 9, 2016, 3:56 p.m.
It's fun to watch you golfing, keep going :)

R2R on March 27, 2017, 9:16 p.m.
Splendid!

przemyslaw.daniel on Aug. 16, 2017, 10:21 a.m.
How about <a href="https://py.checkio.org/mission/pawn-brotherhood/publications/przemyslaw.daniel/python-3/1-liner-change-the-base/edit/">this</a> one which is quite shorter

przemyslaw.daniel on Aug. 16, 2017, 10:30 a.m.
It seems that xiaozhan used this idea before me... I'm a snail ;-)

veky on Aug. 16, 2017, 10:54 a.m.
Yes, that's old trick. :-D

StefanPochmann on Aug. 16, 2017, 11 a.m.
Ah, darn. You linked to your edit-page and CheckiO surprisingly does show me the edit view, but unfortunately nothing happens when I try to re-publish it with my edits :-)

veky on Aug. 16, 2017, 2:14 p.m.
Security is bad, but it's not that bad. :-D

_Chico__5d82cee4f5234e78a5c65e on May 15, 2021, 9:21 a.m.
Oh man, again this unbelievable solution ;)

veky on May 15, 2021, 9:22 a.m.
You're becoming predictable. :-P

Look up in the Dict()

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