There is a straight forward solution if the numbers of 1s are fixed.

I've realized too late that that number is supposed to be free too, so you need recursion (or fake it).

For completeness:

use strict;
use warnings;
use 5.12.0;

my $len = 5;
my $max = $len - 1;

for my $p0 ( 0 .. $max ) {
    for my $p1 ( $p0+1 .. $max ) {
        for my $p2 ( $p1+1 .. $max ) {
            my $str = "0" x $len;
            substr $str, $p0, 1, '1';
            substr $str, $p1, 1, '1';
            substr $str, $p2, 1, '1';
            say "$str $p0 $p1 $p2";
        }
    }
}

[download]

C:/Perl_524/bin\perl.exe -w d:/tmp/pm/bitstrings.pl 
11100 0 1 2
11010 0 1 3
11001 0 1 4
10110 0 2 3
10101 0 2 4
10011 0 3 4
01110 1 2 3
01101 1 2 4
01011 1 3 4
00111 2 3 4

Compilation finished at Fri Sep 18 10:43:25

[download]

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery

In reply to Re: Generate all unique combinations of 1 and 0 using specified length of "0"-string and count of 1's by LanX
in thread Generate all unique combinations of 1 and 0 using specified length of "0"-string and count of 1's by Lana

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