Are there any libraries that provided 2d range trees with fractional cascading, that have O(log n) complexity for range counting queries (i.e., O(log^(d-1) n) for d dimensions)?
One promising coded snippet I found is https://github.com/elazarl/RangeTree/blob/master/src/main/java/com/github/elazarl/rangetree/RangeTree.java - however I can't work out how to modify this code so that I'm only counting, not reporting, the range count.
I know I can do this by adding a count to each leaf, then summing the leaves as I traverse. But I can't figure it out with fractional cascading!