Luís Marques:
It would swap elements, like sort, so it doesn't need to put them anywhere, just permute them. The advantage is this:Input: [7, 3, 7, 1, 1, 1, 1] Output sort: [1, 1, 1, 1, 3, 7, 7] Output groupSort: [3, 7, 7, 1, 1, 1, 1]
I think to swap items it must know where to swap them to. And you can't do that efficiently if the groups are unsorted.
Bye, bearophile
