#23456789_123456789_123456789_123456789_1234
map{$y=$_;map{$s[$_].=$y}$c..$s+$c++}/(.)/g;

##</code><code>##

#23456789_123456789_123456789_123456789_123456789_123456789_12345
@t=/(.)/g;$s=@t<$s?@t:$s;map{$y=$_;map{$f[$_].=$y}$c..$s+$c++}@t;