public IList <IList <int> > GroupThePeople(int[] groupSizes)
{
if (groupSizes.Length < 1 || groupSizes.Length > 500)
{
return(null);
}
var manager = new GroupManager();
for (int i = 0; i < groupSizes.Length; i++)
{
var newPerson = new Person(i, groupSizes[i]);
manager.AddPersonToCorrectGroup(newPerson);
}
return(manager.GetGroupIds());
}