• Andrej Mitrovic <andrej.mitrovich gmail.com> Jun 11 2012
• =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> Jun 11 2012
• "bearophile" <bearophileHUGS lycos.com> Jun 11 2012

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

Is there a Phobos function to turn this:

string[] words = "foo bar doo".split();

into:

string[] res = ["foo bar doo",
                "foo doo bar",
                "bar foo doo",
                "bar doo foo",
                "doo foo bar",
                "doo bar foo"];

So basically all combinations of some number of strings into a string
array. I suppose there's some generic way to do this too.

=?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:

On 06/11/2012 10:41 AM, Andrej Mitrovic wrote:
 Is there a Phobos function to turn this:

 string[] words = "foo bar doo".split();

 into:

 string[] res = ["foo bar doo",
                  "foo doo bar",
                  "bar foo doo",
                  "bar doo foo",
                  "doo foo bar",
                  "doo bar foo"];

 So basically all combinations of some number of strings into a string
 array. I suppose there's some generic way to do this too.


I think "permutation" is a more accurate word in this case. This has 
been discussed before:

   http://forum.dlang.org/thread/ivd4ug$1rmh$1 digitalmars.com

Ali

-- 
D Programming Language Tutorial: http://ddili.org/ders/d.en/index.html

"bearophile" <bearophileHUGS lycos.com> writes:

Andrej Mitrovic:

 string[] words = "foo bar doo".split();

 into:

 string[] res = ["foo bar doo",
                 "foo doo bar",
                 "bar foo doo",
                 "bar doo foo",
                 "doo foo bar",
                 "doo bar foo"];


http://rosettacode.org/wiki/Permutations#Faster_Lazy_Version

Using that the code is:

import std.string, std.stdio, std.array;
void main() {
     auto words = "foo bar doo".split();
     auto res = permutations!false(words).map!(p => p.join(" 
"))().array();
     writeln(res);
}


The output is your desired one:

["foo bar doo", "foo doo bar", "bar foo doo", "bar doo foo", "doo 
foo bar", "doo bar foo"]

Bye,
bearophile