EgyptianMultiplication.clj

(defn halve [i]
  (bit-shift-right i 1))

(defn double [i]
  (bit-shift-left i 1))

(defn mul [x y]
  (let [x (take-while #(not= % 0) (iterate halve x))]
    (->> y
         (iterate double)
         (take (count x))
         (map #(if (odd? %1) %2 0) x)
         (reduce + 0))))