Burrows–Wheeler transformation.

bwt.clj

(defn enhance [s]
  (conj (into [\^] (vec s) )\|))

(defn rotate [c]
  (vec (conj (drop-last c) (last c) )))

(defn pipe-and-save 
  "Given an item, it will recursivly apply fun n times. Gives back item plus each step in a coll"
  ([item n fun]
   (pipe-and-save item n fun []))
  ([item n fun saved]
   (if (= n 0)
     saved
     (let [applied (fun item)]
       (recur applied (dec n) fun (conj saved applied))))))

(defn bwt [c]
  (into [] (map last (sort (pipe-and-save (enhance c) 8 rotate)))))


(bwt "banana")