doubleBooked.clj

(defn doubleBooked [events]
  (let [sortedEvents (sort-by :start events)
        toAdd true
        notToAdd false]
    (loop [head (first sortedEvents)
           isAdd notToAdd
           events (rest sortedEvents)
           intersect []]
      (let [neck (first events)
            tail (rest events)]
        (if (nil? neck)
          (if (= toAdd isAdd)
            (conj intersect head)
            intersect)
          (let [headEnd (head :end)
                neckEnd (neck :end)]
            (if (> (neck :start) headEnd)
              (if (= toAdd isAdd)
                (recur neck notToAdd tail (conj intersect head))
                (recur neck notToAdd tail intersect))
              (if (> headEnd neckEnd)
                (recur head toAdd tail (conj intersect neck))
                (recur neck toAdd tail (conj intersect head))))))))))

Ого, это какой язык? похоже на Lisp, но вроде не он)