- DESCRIPTION
Permute 3.5.8 Multilingual macOS 58 mb. Video, audio and image files come in many different kinds and shapes, but sometimes you need a specific format since your iPad or DVD player won't play that video. That is what Permute is for - easily convert your media files to various different formats.
Permute3.1.3 正式版2019-03-27. For example, the permutations of the digits zero to 3 arranged lexicographically have the following rank: PERMUTATION RANK (0, 1, 2, 3) - 0 (0, 1, 3, 2) - 1 (0, 2.
Math::Permute::Array - Perl extension for computing any permutation of an array. The permutation could be access by an index in [0,cardinal] or by iterating with prev, cur and next.
the output should be:
This module compute the i^{th} permutation of an array recursively. The main advantage of this module is the fact that you could access to any permutation in the order that you want. Moreover this module doesn't use a lot of memory because the permutation is compute. the cost for computing one permutation is O(n).
it could be optimize by doing this iteratively but it seems efficient. Thus this module doesn't need a lot of memory because the permutation isn't stored.
EXPORT
Returns a reference on the index^{th} permutation for the array. This function should be called directly as in the example.
Applies the function on each permutation (this interface is efficient but limited). Deep freeze 7 2019.
Returns a permutor object for the given items.
Called on a permutor, it returns a reference on the array contening the next permutation.
Called on a permutor, it returns a reference on the array contening the previous permutation.
Permute 3 1 18 Equals
Called on a permutor, it returns a reference on the array contening the current permutation.
Called on a permutor, it returns a reference on a array contening index^{th} permutation for the array.
Permute 3 1 18 Inch
Called on a permutor, it returns the number of permutations
Internal functions
returns the factorial of n. This is a internal function to calculate the number of permutations.
jean-noel quintin, <quintin_at_imag_dot_fr>
Copyright (C) 2012 by jean-noel quintin
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.12.4 or, at your option, any later version of Perl 5 you may have available.
To install Math::Permute::Array, copy and paste the appropriate command in to your terminal.
For more information on module installation, please visit the detailed CPAN module installation guide.
Algorithm::Permute - Handy and fast permutation with object oriented interface
This handy module makes performing permutation in Perl easy and fast, although perhaps its algorithm is not the fastest on the earth. It supports permutation r of n objects where 0 < r <= n.
Returns a permutor object for the given items.
Returns a list of the items in the next permutation. The order of the resulting permutation is the same as of the previous version of
Algorithm::Permute
.Returns the list of items which will be returned by next(), but doesn't advance the sequence. Pdf reader 1 58. Could be useful if you wished to skip over just a few unwanted permutations.
Resets the iterator to the start. May be used at any time, whether the entire set has been produced or not. Has no useful return value.
Starting with version 0.03, there is a function - not exported by default - which supports a callback style interface:
A block of code is passed, which will be executed for each permutation. The array will be changed in place, and then changed back again before
permute
returns. During the execution of the callback, the array is read-only and you'll get an error if you try to change its length. (You can change its elements, but the consequences are liable to confuse you and may change in future versions.)You have to pass an array, it can't just be a list. It does work with special arrays and tied arrays, though unless you're doing something particularly abstruse you'd be better off copying the elements into a normal array first. Example:
The code is run inside a pseudo block, rather than as a normal subroutine. That means you can't use
return
, and you can't jump out of it using goto
and so on. Also, caller
won't tell you anything helpful from inside the callback. Such is the price of speed.The order in which the permutations are generated is not guaranteed, so don't rely on it.
The low-level hack behind this function makes it currently the fastest way of doing permutation among others.
I've collected some Perl routines and modules which implement permutation, and do some simple benchmark. The whole result is the following.
Permutation of eight scalars:
Permutation of nine scalars (the Abigail's routine is commented out, because it stores all of the result in memory, swallows all of my machine's memory):
The benchmark script is included in the bench directory. I understand that speed is not everything. So here is the list of URLs of the alternatives, in case you hate this module.
- Memoization is discussed in chapter 4 Perl Cookbook, so you can get it from O'Reilly: ftp://ftp.oreilly.com/published/oreilly/perl/cookbook
- Abigail's: http://www.foad.org/~abigail/Perl
- List::Permutor: http://www.cpan.org/modules/by-module/List
- The classic way, usually used by Lisp hackers: perldoc perlfaq4
In Edwin's words: Yustina Sri Suharini - my ex-fiance-now-wife, for providing the permutation problem to me.
- Data Structures, Algorithms, and Program Style Using C - Korsh and Garrett
- Algorithms from P to NP, Vol. I - Moret and Shapiro
Edwin Pratomo <[email protected]> was the original author.
Stephan Loyd <[email protected]> is co-maintainer after version 0.12.
The object oriented interface is taken from Tom Phoenix's
List::Permutor
. Robin Houston <[email protected]> invented and contributed the callback style interface.This software is copyright (c) 1999 by Edwin Pratomo.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
To install Algorithm::Permute, copy and paste the appropriate command in to your terminal.
For more information on module installation, please visit the detailed CPAN module installation guide.