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in reply to Re: Generate all unique combinations of 1 and 0 using specified length of "0"-string and count of 1's [Updated]
in thread Generate all unique combinations of 1 and 0 using specified length of "0"-string and count of 1's

I might have accidentally broken my previous post, so I just post the final results here. Not because my solutions are faster (tux_a_fp is sloooooow), but as they show TIMTOWTDI

use Algorithm::FastPermute; sub tux_a_fp { my ($length, $ones) = @_; my @l = ((0) x ($length - $ones), (1) x $ones); my %seen; permute { $seen{join "" => @l}++ } @l; [ keys %seen ]; } sub tux_for { my ($length, $ones) = @_; my $s1 = "1" x $ones; my $s0 = "0" x ($length - $ones); [ map { substr unpack ("b*", $_), 0, $length } grep { $ones == unpack "%32b*" => $_ } map { pack "L<", $_ } oct "0b$s1" .. oct "0b$s1$s0" ]; } sub tux_tr { my ($length, $ones) = @_; my $s1 = "1" x $ones; my $s0 = "0" x ($length - $ones); [ grep { $ones == tr/1/1/ } map { substr unpack ("b*", pack "L<",$_), 0, $length } oct "0b$s1" .. oct "0b$s1$s0" ]; }

update: another variation on recursion:

sub tux_recur { my ($length, $ones) = @_; $length or return []; $ones or return [ "0" x $length ]; $ones == $length and return [ "1" x $length ]; [ ( map { "0$_" } @{tux_recur ($length - 1, $ones )} ), ( map { "1$_" } @{tux_recur ($length - 1, $ones - 1)} ), ]; }

On my box ends between Eily and tybalt89. GrandFather is still the fastest:

Discipulus 0.103/s tux_a_fp 1.43/s choroba 1496/s tybalt89_re 1558/s tux_tr 1777/s tux_for 2807/s johngg 2828/s Eily 2851/s tux_recur 2889/s tybalt89 3654/s salva 4187/s Eily_LanX 5110/s GrandFather 6119/s

Enjoy, Have FUN! H.Merijn