>>614　Perl5
use feature say;
for (<DATA>) {
s/\s*//g;
$z = tr/0//;
@a = grep{$_} sort split '';
$a = shift @a;
say join '',($a, (0)x$z, @a);
}
__DATA__
3 2 1
1 2 21
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

execution
$ perl 12_614.pl
123
1122
10111111112233445566789