samboozle

(defn kth-largest [k coll]
  (let [reducer (fn [elems elem]
                  (take k (sort > (conj elems elem))))]
    (last (apply (partial reduce reducer) (split-at k coll)))))
    
(kth-largest 4 (range 100))
;; => returns 96, the 4th-largest element in the range (0, 1, 2, ..., 99)

(kth-largest 100 (take 200 (cycle (range 100))))
;; => returns 50, the 100th-largest element in the collection (0, 0, 1, 1, 2, 2, ..., 99, 99)