#!/usr/bin/perl
permute([qw(one two three four)],[]);
sub permute {
my @items = @{ $_[0] };
my @perms = @{ $_[1] };
unless (@items) {
print "@perms\n";
}else{
my(@newitems, @newperms, $i);
foreach $i (0 .. $#items) {
@newitems = @items;
@newperms = @perms;
unshift(@newperms, splice(@newitems, $i, 1));
permute([@newitems], [@newperms]);
}
}
}
実行結果
# perl permute.pl four three two one three four two one four two three one two four three one three two four one two three four one four three one two three four one two four one three two one four three two three one four two one three four two four two one three two four one three four one two three one four two three two one four three one two four three three two one four two three one four three one two four one three two four two one three four one two three four
なるほど・・・が、ソースの意味がほとんどわからない・・・。