[#406419] Recursion with Hash — Love U Ruby <lists@...>

h = {a: {b: {c: 23}}}

14 messages 2013/04/01

[#406465] Exclusively for Rubyists, a community on Facebook — "senthil k." <lists@...>

I was surprised to know that there is no community for Ruby Programming

12 messages 2013/04/03
[#406467] Re: Exclusively for Rubyists, a community on Facebook — Marc Heiler <lists@...> 2013/04/04

Thing is, some people do not use Facebook and never will.

[#406528] Role of bundler in creating and installing a gem — Jon Cairns <lists@...>

Hi fellow rubyists,

11 messages 2013/04/05

[#406555] How do you know what the main file in Ruby Projects is? — peteV <pete0verse@...>

Hi Ruby people,

18 messages 2013/04/05
[#406558] Re: How do you know what the main file in Ruby Projects is? — "Carlo E. Prelz" <fluido@...> 2013/04/05

Subject: How do you know what the main file in Ruby Projects is?

[#406560] Re: How do you know what the main file in Ruby Projects is? — Hans Mackowiak <lists@...> 2013/04/05

Carlo E. Prelz wrote in post #1104616:

[#406562] Re: How do you know what the main file in Ruby Projects is? — "D. Deryl Downey" <me@...> 2013/04/05

Actually its not wrong. What it does is explicitly state which ruby

[#406563] Re: How do you know what the main file in Ruby Projects is? — Matt Lawrence <matt@...> 2013/04/05

On Sat, 6 Apr 2013, D. Deryl Downey wrote:

[#406564] Re: How do you know what the main file in Ruby Projects is? — Hans Mackowiak <lists@...> 2013/04/05

Matt Lawrence wrote in post #1104625:

[#406566] Re: How do you know what the main file in Ruby Projects is? — Matt Lawrence <matt@...> 2013/04/05

On Sat, 6 Apr 2013, Hans Mackowiak wrote:

[#406570] Re: How do you know what the main file in Ruby Projects is? — Matthew Mongeau <halogenandtoast@...> 2013/04/05

I'm interested in the issue with using env, but I find you explanation a but=

[#406600] Mapping string data ptr to buffer in ffi — se gm <lists@...>

I'm trying to implement some "shared memory" in Ruby, but I'm not sure

20 messages 2013/04/08

[#406683] confusion with Struct class — Love U Ruby <lists@...>

I went to there - http://www.ruby-doc.org/core-2.0/Struct.html but the

29 messages 2013/04/11
[#406694] Re: confusion with Struct class — Love U Ruby <lists@...> 2013/04/11

Why does every time the has value getting changed,while the instance

[#406762] Why does #content method in nokogiri not printing the full text? — Love U Ruby <lists@...>

Here is the documentation: http://www.rubydoc.info/gems/nokogiri/frames

19 messages 2013/04/14
[#406764] Re: Why does #content method in nokogiri not printing the full text? — tamouse mailing lists <tamouse.lists@...> 2013/04/14

On Sun, Apr 14, 2013 at 11:19 AM, Love U Ruby <lists@ruby-forum.com> wrote:

[#406874] Input: sentence Modify: words Output: modified sentence — Philip Parker <lists@...>

I am new to Ruby. This is a programming interview question to use any

11 messages 2013/04/19

[#406912] Tap method : good or bad practice ? — Sébastien Durand <lists@...>

Hi all !

18 messages 2013/04/21

[#406936] BEGINNER -CLASS QUERY — shaik farooq <lists@...>

HEY as we know that the object conatins the instance variables that are

22 messages 2013/04/22

[#406966] copying files syntax with FileUtils.rb (grr.) — Thomas Luedeke <lists@...>

In my Ruby scripting, there is probably no greater and chronic source of

10 messages 2013/04/23

[#406969] what is the $- magic global? — Matthew Kerwin <lists@...>

I've been searching for the past hour or so, including manually stepping

13 messages 2013/04/24

[#407059] New Rexx like data structure — Peter Hickman <peterhickman386@...>

This is just something that I have been playing with for some time but I

11 messages 2013/04/29

[#407070] writing lines to a file — peteV <pete0verse@...>

I have a text file with on every line a magic card number and such info

13 messages 2013/04/29

Re: Looking for more elegant solutions.

From: tamouse mailing lists <tamouse.lists@...>
Date: 2013-04-13 19:17:56 UTC
List: ruby-talk #406755
Hi, Pablo -- I wasn't the OP, I was just wondered about limits.

On Sat, Apr 13, 2013 at 12:52 PM, Pablo Bianciotto <lists@ruby-forum.com> wrote:
> This would improve performance by removing the delete_if iteration over
> the full array. But it still won't work for n > 10:
>
> =begin
>
> out = []
> 1..n).to_a.permutation do |perm|
>   out << perm unless perm.any? { |letter| letter == perm[letter -1] }
> end
> out
>
> =end
>
> Do you need to have all the permutations  allocated in an array? If you
> don't, maybe you should try building an enumerator to ask for the next
> one each time you need one. You could also use Enumerator#lazy if you
> are using ruby 2.0.
>
> Anyway, without delete_if this approach it's almost twice as fast as
> your original code.
>
> =begin
>
> require "benchmark"
>
> def f( already, n, times )
>   if n > times
>     $nums << already.dup
>     return
>   else
>     1.upto(times) do |i|
>       next if ((already.include? i) || n == i)
>       already << i
>       f( already, n+1, times )
>       already.pop
>     end
>   end
> end
>
> Benchmark.bm(15) do |x|
>   (8..11).each do |n|
>     x.report("new_perm N = #{ n }:") do
>       out = []
>       (1..n).to_a.permutation do |perm|
>         out << perm unless perm.any? { |letter| letter == perm[letter
> -1] }
>       end
>       out
>     end
>     x.report("original N = #{ n }:") do
>       $nums = []
>       f([],1,n)
>       $nums
>     end
>     if n < 10
>       x.report("old_perm N = #{ n }:") do
>         1.upto(n).to_a.permutation(n).to_a.delete_if do |perm|
>           perm.any? { |letter| letter == perm[letter -1] }
>         end
>       end
>     end
>   end
> end
>
> =end
>
>                       user     system      total        real
> new_perm N = 8:   0.031000   0.000000   0.031000 (  0.043003)
> original N = 8:   0.078000   0.000000   0.078000 (  0.078004)
> old_perm N = 8:   0.250000   0.000000   0.250000 (  0.242014)
> new_perm N = 9:   0.421000   0.000000   0.421000 (  0.422024)
> original N = 9:   0.795000   0.000000   0.795000 (  0.803046)
> old_perm N = 9:  16.490000   0.000000  16.490000 ( 16.499944)
> new_perm N = 10:  5.085000   0.015000   5.100000 (  5.076290)
> original N = 10:  9.594000   0.016000   9.610000 (  9.608550)
> new_perm N = 11: 66.644000   0.265000  66.909000 ( 67.106838)
> original N = 11:[FATAL] failed to allocate memory
>
> Hope it helps!
> Pablo B.
>
> --
> Posted via http://www.ruby-forum.com/.
>

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