2013-04-10 21:29:02 -07:00
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(defn happy? [n]
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(loop [n n, seen #{}]
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2015-02-20 00:35:01 -05:00
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(cond
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(= n 1) true
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(seen n) false
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:else
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(recur (->> (str n)
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(map #(Character/digit % 10))
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(map #(* % %))
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(reduce +))
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(conj seen n)))))
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2013-04-10 21:29:02 -07:00
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(def happy-numbers (filter happy? (iterate inc 1)))
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(println (take 8 happy-numbers))
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