http://www.perlmonks.org?node_id=77970


in reply to (Golf) Per Mutations

A non-recursive solution, 138 characters, and doesn't suffer from problems with repeated elements.
#!/usr/bin/perl -w use strict; use Data::Dumper; my @b = p( 1, 2, 3 ); print Dumper( @b ); sub p { my@a=[];for(0..@_){@a=map{my@b=@$_;my@c=@_;for(@b){my$e=$_;for(1..@c +){my$d=shift@c;last if$d eq$e;push @c,$d}}@c?map{[@b,$_]}@c:[@b]}@a}@ +a }

Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain

Replies are listed 'Best First'.
Re (tilly) 2: (Golf) Per Mutations
by tilly (Archbishop) on May 04, 2001 at 19:16 UTC
    Non-recursive, handles repeated elements?
    sub permute{ @r=[];$e=$_,@r=map{@a=@$_;map{@b=@a;splice(@b,$_,0,$e);[@b]}0..@a}@r f +or@_;@r }
    77 chars...

    UPDATE
    75...

    sub permute{ @r=[];$e=$_,@r=map{@a=@$_;map[@a[0..$_-1],$e,@a[$_..$#a]],0..@a}@r for +@_;@r }