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Move-to-front algorithm: Difference between revisions
Adds Clojure solution
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}
</lang>
=={{header|Clojure}}==
<lang clojure>(def lowercase (map char (range (int \a) (inc (int \z)))))
(defn move-to-front [x xs]
(cons x (remove #{x} xs)))
(defn encode [text table & {:keys [acc] :or {acc []}}]
(let [c (first text)
idx (.indexOf table c)]
(if (empty? text) acc (recur (drop 1 text) (move-to-front c table) {:acc (conj acc idx)}))))
(defn decode [indices table & {:keys [acc] :or {acc []}}]
(if (empty? indices) (apply str acc)
(let [n (first indices)
c (nth table n)]
(recur (drop 1 indices) (move-to-front c table) {:acc (conj acc c)}))))
(doseq [word ["broood" "bananaaa" "hiphophiphop"]]
(let [encoded (encode word lowercase)
decoded (decode encoded lowercase)]
(println (format "%s encodes to %s which decodes back to %s."
word encoded decoded))))</lang>
{{Out}}
<pre>
broood encodes to [1 17 15 0 0 5] which decodes back to broood.
bananaaa encodes to [1 1 13 1 1 1 0 0] which decodes back to bananaaa.
hiphophiphop encodes to [7 8 15 2 15 2 2 3 2 2 3 2] which decodes back to hiphophiphop.
</pre>
=={{header|Common Lisp}}==
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