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2016 Update

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Tina Müller 2016-12-05 22:15:40 +01:00
parent 948b86eafa
commit dcf5d15da3
7965 changed files with 139854 additions and 31002 deletions
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18
Task/Stern-Brocot-sequence/Clojure/stern-brocot-sequence-1.clj Normal file
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;; compute the Nth (1-based) Stern-Brocot number directly
(defn nth-stern-brocot [n]
(if (< n 2)
n
(let [h (quot n 2) h1 (inc h) hth (nth-stern-brocot h)]
(if (zero? (mod n 2)) hth (+ hth (nth-stern-brocot h1))))))
;; return a lazy version of the entire Stern-Brocot sequence
(defn stern-brocot
([] (stern-brocot 1))
([n] (cons (nth-stern-brocot n) (lazy-seq (stern-brocot (inc n))))))
(printf "Stern-Brocot numbers 1-15: %s%n"
(clojure.string/join ", " (take 15 (stern-brocot))))
(dorun (for [n (concat (range 1 11) [100])]
(printf "The first appearance of %3d is at index %4d.%n"
n (inc (first (keep-indexed #(when (= %2 n) %1) (stern-brocot)))))))