private static void CollectSets(FastList <int> packages, int target, List <int> group, List <int[]> collection)
{
FastList <int> workingSet = new(packages);
packages.ForEach(package =>
{
workingSet = workingSet.Without(package);
group.Add(package);
int sum = Sum(group);
if (sum == target)
{
collection.Add(group.ToArray());
}
else if (sum < target)
{
CollectSets(workingSet, target, group, collection);
}
group.Remove(package);
});
}
