sub Solve
{
  my ($goal, $elements) = @_;

  # For extra speed, you can remove this next line

  my (@results, $RecursiveSolve, $nextValue);

  $RecursiveSolve = sub {
    my ($currentGoal, $included, $index) = @_;

    for ( ; $index < @$elements; ++$index) {
      $nextValue = $elements->[$index];
      # Since elements are sorted, there's no point in trying a
      # non-final element unless it's less than goal/2:
      if ($currentGoal > 2 * $nextValue) {
        $RecursiveSolve->($currentGoal - $nextValue,
                          [ @$included, $nextValue ],
                          $index + 1);
      } else {
        print "@$_\n", [ @$included, $nextValue ]
            if $currentGoal == $nextValue;
        return if $nextValue >= $currentGoal;
      }
    } # end for
  }; # end $RecursiveSolve

  $RecursiveSolve->($goal, [], 0);
  undef $RecursiveSolve; # Avoid memory leak from circular reference
  return @results;
} # end Solve


my @results = Solve(869, [15, 43, 51, 56, 60, 67, 122, 152, 193, 204, 229, 271, 293, 301]
);