Sleep sort is certainly not O(1), even if there's some disagreement of the correct way of describing it. See https://stackoverflow.com/questions/6474318/what-is

Sleep sort is certainly not O(1), even if there's some disagreement of the correct way of describing it. See https://stackoverflow.com/questions/6474318/what-is-the-time-complexity-of-the-sleep-sort https://stackoverflow.com/questions/6474318/what-is-the-time... for some discussion. If you want to call it O(1), by the same approach you could call any finite algorithm O(1).