This reminded me of the card shuffling algorithm from Sedgewick http://algs4.cs.princeton.edu/lectures/21ElementarySorts.pdf http://algs4.cs.princeton.edu/lect

This reminded me of the card shuffling algorithm from Sedgewick http://algs4.cs.princeton.edu/lectures/21ElementarySorts.pdf http://algs4.cs.princeton.edu/lectures/21ElementarySorts.pdf In that he assigns a random number to each element. Sorts the elements based on the random number. Then takes the first N elements from the beginning.