The Test

the-test.clj

;; https://hackernoon.com/how-to-lose-an-it-job-in-10-minutes-3d63213c8370

(defn set-rotated
  "Returns a set of all possible rotations of a string"
  [s]
  (loop [i 0
         acc #{}]
    (if (= i (count s))
      acc
      (recur (inc i) (conj acc (->> s cycle (drop i) (take (count s)) (apply str)))))))

(defn group-rotated
  "Groups strings so that each group contains the strings
  that are rotations of one another."
  [coll]
  (->> coll
       (map set-rotated)
       (interleave coll)
       (partition 2)
       (reduce (fn
                 [acc [orig rotated-set]]
                 (let [found (get acc rotated-set [])]
                   (assoc acc rotated-set (conj found orig))))
               {})
       vals))