HackerRank Median Clojure (passes)

gistfile1.clj

(ns solution (:gen-class))

(set! *warn-on-reflection* true)

(defn median [^java.util.PriorityQueue max-heap ^java.util.PriorityQueue min-heap]
  (let [max-size (.size max-heap)
        min-size (.size min-heap)]
    (cond 
      (and (zero? max-size)
           (zero? min-size)) "Wrong!"
      (= max-size min-size) (/ (+ (.peek min-heap) (.peek max-heap)) 2)
      :else (.peek max-heap))))

(defn balance-heap [^java.util.PriorityQueue max-heap ^java.util.PriorityQueue min-heap]
  ; (println "balance: " max-heap min-heap)
  (let [max-size (.size max-heap)
        min-size (.size min-heap)]
    (cond
      (zero? max-size) nil
      (> max-size (inc min-size)) (.add min-heap (.poll max-heap))
      (< max-size min-size) (.add max-heap (.poll min-heap))
      (and (pos? min-size)
           (> max-size min-size)
           (> (.peek max-heap) (.peek min-heap)))
        (let [max-root (.poll max-heap)
              min-root (.poll min-heap)]
          (.add min-heap max-root)
          (.add max-heap min-root)))))

(defn ^String format-answer [x]
  (if (instance? clojure.lang.Ratio x)
    (format "%.1f" (double x))
    (str x)))

(defn solve [src dest]
  (let [in (clojure.java.io/reader src)
        out (clojure.java.io/writer dest)
        _ (.readLine in)
        min-heap (java.util.PriorityQueue. 1000)
        max-heap (java.util.PriorityQueue. 1000 (java.util.Collections/reverseOrder))]
    (try
      (loop [seen (hash-set)]
        (let [op (.read in)
              _ (.read in)
              n (Integer/parseInt (.readLine in))]
          (case op
            114 (if (and (contains? seen n)
                         (if (<= n (.peek max-heap))
                           (.remove max-heap n)
                           (.remove min-heap n)))
                  (do
                    (balance-heap max-heap min-heap)
                    (.write out (format-answer (median max-heap min-heap)))
                    (.newLine out)
                    (recur seen))
                  (do
                    (.write out "Wrong!\n")
                    (recur seen)))
            97 (do 
                 (.add max-heap n)
                 (balance-heap max-heap min-heap)
                 (.write out (format-answer (median max-heap min-heap)))
                 (.newLine out)
                 (recur (conj seen n))))))
      (catch Exception e)
      (finally (.flush out)))))

(defn -main []
  (solve *in* *out*))

;(time (solve "/Users/kanwei/Projects/istreet/median/input01.txt" (doto (java.io.File/createTempFile "medians" ".out") .deleteOnExit)))
;(time (solve "/Users/kanwei/Projects/istreet/median/worst.txt" (doto (java.io.File/createTempFile "medians" ".out") .deleteOnExit)))
;(time (solve "/Users/kanwei/Projects/istreet/median/input01.txt") *out*)