How do I get the sequence of numbers in a sorted-set that are between two integers in clojure?
- by Greg Rogers
Say I have a sorted-set of integers, xs, and I want to retrieve all the integers in xs that are [x, y), ie. between x and y.
I can do:
(select #(and (>= % x) (< % y)) xs)
But this is inefficient - O(n) when it could be O(log n), I expect the number of elements returned to be small. Using take-while and drop-while would let me exit once I've reached y, but I still can't jump to x efficiently.
I am just learning clojure so here is how I would do it in C++:
set<int>::iterator first = xs.lower_bound(x);
set<int>::iterator last = xs.lower_bound(y);
for (; first != last; ++first)
// do something with *first
Can I do this in clojure?
