4clojure problem #53

p53-longest-increasing-sub-seq.clj

; 2013-11-29 SOLVED
(defn p53-longest-increasing-sub-seq [s]
  (let [begin-sequences
        (fn [s] (rest (reductions (fn [a b] (conj a b)) [] s)))
        end-sequences
        (fn [s] (reverse (reduce (fn [mem a] (conj (map (fn [b] (flatten [b a])) mem) (list a))) [] s)))
        longest
        (fn [s] (reduce (fn [longest x] (if (> (count x) (count longest)) x longest)) [] s))]
    (->> (apply concat (map begin-sequences (end-sequences s)))
         (filter (fn [s] (apply < s)))
         (filter (fn [s] (> (count s) 2)))
         (longest)
         )))