Stalin Sort

stalinsort.py

def stalinsort(unsorted):
    """Stalin sort: O(n) sort algorithm that iterate down a
    list of elements, any element which is out of order is
    eliminated.
    https://www.facebook.com/ProgrammersCreateLife/photos/a.241809332534619/1934139766634892/?type=1&theater
  
    Args:
        unsorted: Iterable of elements that support >= operator
    Returns:
        A list of subset of the input
    """
    output = []
    for x in unsorted:
        if not output or x >= output[-1]:
            output.append(x)
    return output