;; ariarule's solution to Intervals ;; https://4clojure.com/problem/171 ;; Slightly bleh

gistfile1.clj

(fn [s]
  (vec (apply sorted-set (map vec (let [t (set (sort s))
        w (rest (butlast t))
        v (sort (if (empty? t) t (cons (first t) (conj (vec (map first
                                       (remove
                                         #(and (contains? (second %) 1) (contains? (second %) -1))
                                         (reduce #(assoc %1 %2 (set (map (partial - %2) t))) {} w)))) (last t)))))]
    (if (empty? v)
      v
      (partition 2 (reverse (reduce
          #(if (or (t (dec %2)) (t (inc %2)))
             (cons %2 %1)
             (cons %2 (cons %2 %1)))
          []
          v)))))))))