Cassidy's Interview Question - 31/5/20

poweroftwo.clj

;; Just wanted to take a different approach to using 
;; logarithms or recursively dividing...

;; powers of 2, in binary, have only 1 bit as "1", so I'll look for just that!

(require '[clojure.string :as str])

(defn is-power-of-2?
  "Returns true if n is a power of 2"
  [n]
  (let [bin-str (Integer/toBinaryString n)
        count-1s (count (filter #(= "1" %) (str/split bin-str #"")))]
    (if (= count-1s 1)
      (println "IT IS A POWER OF 2!")
      (println "IT IS A POWER OF SOME OTHER NUMBER *(Maybe)"))))

(is-power-of-2? 40)
(is-power-of-2? 64)