It is a sorting algorithm that is of humorous nature and not useful. It's based on the principle of multiply and surrender, a tongue-in-cheek joke of divide and conquer. It was published in 1986 by Andrei Broder and Jorge Stolfi in their paper Pessimal Algorithms and Simplexity Analysis.
It is interesting because it is provably the least efficient sorting algorithm that can be built asymptotically, and with the restriction that such an algorithm, while being slow, must still all the time be working towards a result. Every move is a right move working towards the solution, unlike BogoSort, yet still slow.
The runtime T(n) for Slowsort is T(n) = 2 T(n/2) + T(n-1) + 1 .
