lcm - Perl - least common multiple -

this code should lcm n numbers.

i tried put prints wherever can in order see mistake. , think in:

if($vec[0] == $vec[$n-1]){     $resultado = $vec[0];     last; }

but can not make work. please me?

i'm rookie perl. hope can solve problem.
tried change variables not work. mean

$u = 0 , $w = $n-1;

to lcm, can split task multiple subroutines:

is_prime # returns true if value prime
roots # returns roots of number (all prime numbers make value. ex: roots of 12 are: 2, 2, 3)
lcm # takes list of values. extract roots while number not prime. store in hash , increment everytime see root

so we'll have hash like:

%sub_total = (   value => times_found,   2 => 2,   3 => 1, );

we have hash total. if sub_total hash has key used more in total hash, add total.

finally, loop through total hash , and find product using algorithm:

for (%total){    $prod *= $_ ** $total {$_}; }

note

i'll shortly attach code wrote getting lcm. it's not me here.