[Ruby] Fibonacci 數列....
[b][i]新聞群組： [url=http://groups.google.com/group/comp.lang.ruby]comp.lang.ruby[/url]"Peter Ertl" <p...@gmx.org>
日期： Thu, 15 Dec 2005 03:16:29 +0900
主旨： ruby beats them all[/i][/b]
that why I love ruby (and functional languages in general)
[code]def fibonacci(n)
a, b = 1, 1
n.times do
a, b = b, a + b
end
a
end [/code]
elegance beats ignorance (ruby vs. java)
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[b][i]Christian Neukirchen <chneukirc...@gmail.com>
日期：Thu, 15 Dec 2005 04:27:08 +0900[/i][/b]
That's not functional...
How about really doing it functional?
[code]def fib(n)
(1..n-2).inject([1, 1]) { |(a, b), n| [b, a+b] }.last
end [/code]
:)
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[b][i]Edward Faulkner <e...@alum.mit.edu>
日期： Thu, 15 Dec 2005 04:58:15 +0900[/i][/b]
If we're talking about elegance, I prefer this one. It reads just
like the definition of the sequence:
[code]def fib(n)
n > 1 ? fib(n-1) + fib(n-2) : n
end [/code]
You can even make it run efficiently by memoizing it. :-)
-Ed
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[b][i]"Andrew Backer" <awbac...@gmail.com>
日期： 14 Dec 2005 22:37:43 -0800[/i][/b]
[code]def calc_iterative(n)
a = [0,1,0]
for i in 2..n
a[k] = a[k-1] + a[k-2]
end
return a[n%3]
end [/code]
I like this one, since it uses array wrapping. So many ways to write
it that are all *slightly* different... But this was to show someone,
so :)
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