(defn calculate-row
  [data rows]
  (loop [d data
         r rows]
    (if (= (rest d) ())
      r)
    (cond
      (= (first d) \F) (recur (rest d) (bottom r))
      (= (first d) \B) (recur (rest d) (top r)))))

(defn bottom [rows]
  (first (partition (quot (count rows) 2) rows)))

(defn top [rows]
  (second (partition (quot (count rows) 2) rows)))


(calculate-row (char-array "FBFBBFF") (range 0 128))