Question

What is the most efficient way to sort a list, [0,0,1,0,1,1,0] whose elements are only 0 & 1, without using any builtin sort() or sorted() or count() function. O(n) or less than that

Answer 1

>>> lst = [0,0,1,0,1,1,0]
>>> l, s = len(lst), sum(lst)
>>> result = [0] * (l - s) + [1] * s
>>> result
[0, 0, 0, 0, 1, 1, 1]