rendezvous with cassidoo challenge: 24.08.05

squares.clj

(ns squares
  (:require [clojure.test   :refer [deftest is]]
            [criterium.core :as cc]))
   
 (defn squares [n]
  (let [nums (range 1 (inc n))]
    (->> nums
         (map #(* % %))
         (reduce +))))

(deftest squares-test
  (is (= 55 (squares 5)))
  (is (= 385 (squares 10)))
  (is (= 5525 (squares 25)))
  (is (= 338350 (squares 100))))

(defn squares-tranduce [n]
  (let [nums (range 1 (inc n))]
    (transduce (map #(* % %)) + nums)))

(deftest squares-tranduce-test
  (is (= 55 (squares-tranduce 5)))
  (is (= 385 (squares-tranduce 10)))
  (is (= 5525 (squares-tranduce 25)))
  (is (= 338350 (squares-tranduce 100))))


(comment
  (cc/quick-bench (squares 100000))          ;; => ~2.85 ms
  (cc/quick-bench (squares-tranduce 100000)) ;; => ~1.85 ms
  (/ 2.85 1.85) ;; transducer approach is 1.54x faster
  ,)