@cols[1 .. $#cols] = map(tr /[1,2]/[0,1]/, @cols)

##</code><code>##

my %data;
while (<DATA>) {
    next if /^id/;
    my ($id, @cols) = split; ## first split
    my $cols = join('',@cols); ## Join 
    @cols = split('',$cols); ## and then split
    push @{ $data{$id} }, \@cols;
}