I haven't thought about it closely but, from a cursory read, it sounds like the SquareList data structure: http://www.drdobbs.com/database/the-squarelist-data-s

I haven't thought about it closely but, from a cursory read, it sounds like the SquareList data structure: http://www.drdobbs.com/database/the-squarelist-data-structure/184405336 http://www.drdobbs.com/database/the-squarelist-data-structur...