Re: Fibonacci golf with one state variable

in reply to Fibonacci golf with one state variable

Without eval, without quotes, without explicit assignment and without arithmetic:

perl -lE 's//:o/;say length$1 while s/(.*):(.*)/$2:$1$2/'
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Comment on Re: Fibonacci golf with one state variable Download Code

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Re^2: Fibonacci golf with one state variable by aufflick (Deacon) on Oct 05, 2008 at 11:54 UTC
Hey that's neat! Of course the memory usage is far from constant, but great idea. Good use of `say` to save a few. Only nitpicks are that you do have explicit initialisation and the first output is zero which is not quite right. Oddly, I get no output unless I tweak it to print to STDERR which is some strange buffering difference - no idea why. ++ for thinking laterally :)	[reply] [d/l]
Re^3: Fibonacci golf with one state variable by JavaFan (Canon) on Oct 05, 2008 at 13:21 UTC
Well, I'd argue that not outputting zero isn't quite right. Usually, the Fibonacci sequence is defined as F(0) = 0; F(1) = 1; F(n) = F(n-1) + F(n-2), n > 1. See for instance Sloane: The On-Line Encyclopedia of Integer Sequences and Graham, Knuth and Patashnik in Concrete Mathematics. Eric Weisstein defines the sequence as starting with F(1) = F(2) = 1 and then states it's conventional to define F(0) = 0.	[reply]
Re^4: Fibonacci golf with one state variable by aufflick (Deacon) on Oct 06, 2008 at 03:13 UTC
Can't fault your references!	[reply]
Re^2: Fibonacci golf with one state variable by ikegami (Patriarch) on Oct 05, 2008 at 12:18 UTC
Heh! I had come up with exactly that! It's not shorter, though. And boy does it get slow fast. Save a char by dropping the "l" in "-lE". Save a char by dropping the space after "-E".	[reply]
Re^2: Fibonacci golf with one state variable by ambrus (Abbot) on Oct 15, 2009 at 17:39 UTC
See also Fibonacci numbers using regexes (threes are wild).	[reply]

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