use strict;
use warnings;
use Math::Combinatorics;

my @array = (6, 18, 12, 2, 49);
my @sums = (30, 18);

for my $target (@sums)
  {
  for (1..@array)
    {
    my @combs = Math::Combinatorics::combine ($_, @array);
    for my $comb (@combs)
      {
      my $sum = 0;
      map {$sum += $_} @$comb;
      next if $sum != $target;
      print "$target = " . (join " + ", @$comb) . "\n";
      }
    }
  }
[download]

30 = 12 + 18
18 = 18
18 = 12 + 6
[download]