project euler 86

pe_86.clj

;; Problem 86  : 2012/07/24
;; "Elapsed time: 2840.618843 msecs"

(defn is-pethagorean [x y]
  (let [hypo (Math/sqrt (+ (* x x) (* y y)))]
    (if (== 0 (rem hypo 1) )
      (int hypo)
      nil)))

(defn count-cuboids [a+b c]
  (+ 1
     (- (if (< a+b c) (dec a+b) c)
        (if (odd? a+b) (/ (inc a+b) 2) (/ a+b 2)))))

(defn count-all-cuboids [c]
  (->> (range 2 (inc (* 2 c)))
       (filter (partial is-pethagorean c) ,,)
       (map #(count-cuboids % c) ,,)
       (reduce + ,,)))


(defn pe86 [tacget-count]
  (loop [cuboids-count 0, max-length 0]
    (if (> cuboids-count tacget-count)
      [max-length cuboids-count] 
      (recur (+ cuboids-count
                (count-all-cuboids (inc max-length)))
             (inc max-length)))))