This doesn't have to be complicated. Split on * and before /, then check for /\^\d+$/:
` my @units= split m#(?<=.)(?:(?=/)|\*)#, $units, -1;
my %power;
for my $unit ( @units ) {
my $power= 1;
if( $unit =~ s#\^(\d+)$## ) {
$power= $1;
}
if( $unit =~ s#^/## ) {
$power= -$power;
}
$power{$unit} += $power;
}
# ...
`
then you have to find units that you can convert to with matching powers. So, if you start with kg/cm/sec [ which becomes (kg=>1,cm=>-1,sec=>-1) ] and are asked to return lb/ft/hr (lb=>1,ft=>-1,hr=>-1), then you have to convert from kg to lb, then convert cm to either ft or hr (there will be no cm-to-hr path so you'll do cm-to-ft), then convert the left-overs, sec-to-hr. And you're done.
(**Updated** and tested.)
- tye | [reply] [d/l] |