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stuartstein777/sieve.clj

Created February 24, 2021 21:19
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sieve of erastothanes
Raw
sieve.clj
;; slow :(
(defn sieve-primes [upper]
(let [xs (->> (range 1 (inc upper))
(set))]
(sort (reduce #(if (or (= 1 %2) (not (%1 %2)))
%1
(let [multiples (range (* 2 %2) (inc upper) %2)]
(set/difference %1 multiples))) xs (range 1 (Math/sqrt (inc upper)))))))
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