(defn lis
  "Attempt at solving 4clojure problem #53"
  ([s] (lis [s #{} []]))
  ([s candidates curr]
    (if (empty? s)
      (reduce #((if (> (count %1) (count %2)) %1 %2)) [] candidates)
      (if (empty? curr)
        (recur (rest s) candidates [(first s)])
        (if (> (first s) (last curr))
          (recur (rest s) candidates (concat curr [(first s)]))
          (if (> (count curr) 1)
            (recur (rest s) (conj candidates curr) [])
            (recur (rest s) candidates [])))))))

(lis [1 3 4 5 3 2])