pangloss · May 12, 2013 18:34
diff --git a/euler-59.clj b/euler-59.clj
 (ns euler-59)

 (defn decryptions [data]
  (let [chrs (range (int \a) (inc (int \z)))]
    (for [a chrs b chrs c chrs]
         (let [k (cycle [a b c])]
           (map (fn [a b] (bit-xor a b)) data k)))))

 ; Doesn't take much to validate english!
 (defn possibly-valid? [str]
  (re-find #"(?i: or )" str))

 (defn eulerize [data]
  (->> data
       decryptions
       ; this next step is a massive speedup. Each possible decryption is a
       ; *lazy-seq*, so if I can filter it out without fully executing it,
       ; I can save a lot of work. On my machine, moving the following 3 lines from
       ; inside decryptions to here improved the speed to solution from 2100ms to 33ms.
       (filter (fn [stream] (not-any? #(< (int \z) %) stream)))
       (map #(map char %))
       (map clojure.string/join)
       (filter possibly-valid?)
       first
       (map int)
       (apply +)))


 (defn run []
  ; too lazy to bather with reading the csv
  (let [data [79 59 12 2 79 35 8 28 20 2 3 68 8 9 68 45 0 12 9 67 68 4 7 5 23 27 1 21 79 85 78 79 85 71 38 10
              71 27 12 2 79 6 2 8 13 9 1 13 9 8 68 19 7 1 71 56 11 21 11 68 6 3 22 2 14 0 30 79 1 31 6 23 19 10 0
              73 79 44 2 79 19 6 28 68 16 6 16 15 79 35 8 11 72 71 14 10 3 79 12 2 79 19 6 28 68 32 0 0 73 79 86
              71 39 1 71 24 5 20 79 13 9 79 16 15 10 68 5 10 3 14 1 10 14 1 3 71 24 13 19 7 68 32 0 0 73 79 87 71
              39 1 71 12 22 2 14 16 2 11 68 2 25 1 21 22 16 15 6 10 0 79 16 15 10 22 2 79 13 20 65 68 41 0 16 15 6
              10 0 79 1 31 6 23 19 28 68 19 7 5 19 79 12 2 79 0 14 11 10 64 27 68 10 14 15 2 65 68 83 79 40 14 9
              1 71 6 16 20 10 8 1 79 19 6 28 68 14 1 68 15 6 9 75 79 5 9 11 68 19 7 13 20 79 8 14 9 1 71 8 13 17
              10 23 71 3 13 0 7 16 71 27 11 71 10 18 2 29 29 8 1 1 73 79 81 71 59 12 2 79 8 14 8 12 19 79 23 15 6
              10 2 28 68 19 7 22 8 26 3 15 79 16 15 10 68 3 14 22 12 1 1 20 28 72 71 14 10 3 79 16 15 10 68 3 14 22
              12 1 1 20 28 68 4 14 10 71 1 1 17 10 22 71 10 28 19 6 10 0 26 13 20 7 68 14 27 74 71 89 68 32 0 0 71
              28 1 9 27 68 45 0 12 9 79 16 15 10 68 37 14 20 19 6 23 19 79 83 71 27 11 71 27 1 11 3 68 2 25 1 21
              22 11 9 10 68 6 13 11 18 27 68 19 7 1 71 3 13 0 7 16 71 28 11 71 27 12 6 27 68 2 25 1 21 22 11 9 10
              68 10 6 3 15 27 68 5 10 8 14 10 18 2 79 6 2 12 5 18 28 1 71 0 2 71 7 13 20 79 16 2 28 16 14 2 11 9
              22 74 71 87 68 45 0 12 9 79 12 14 2 23 2 3 2 71 24 5 20 79 10 8 27 68 19 7 1 71 3 13 0 7 16 92 79 12
              2 79 19 6 28 68 8 1 8 30 79 5 71 24 13 19 1 1 20 28 68 19 0 68 19 7 1 71 3 13 0 7 16 73 79 93 71 59
              12 2 79 11 9 10 68 16 7 11 71 6 23 71 27 12 2 79 16 21 26 1 71 3 13 0 7 16 75 79 19 15 0 68 0 6 18 2
              28 68 11 6 3 15 27 68 19 0 68 2 25 1 21 22 11 9 10 72 71 24 5 20 79 3 8 6 10 0 79 16 8 79 7 8 2 1 71
              6 10 19 0 68 19 7 1 71 24 11 21 3 0 73 79 85 87 79 38 18 27 68 6 3 16 15 0 17 0 7 68 19 7 1 71 24 11
              21 3 0 71 24 5 20 79 9 6 11 1 71 27 12 21 0 17 0 7 68 15 6 9 75 79 16 15 10 68 16 0 22 11 11 68 3 6
              0 9 72 16 71 29 1 4 0 3 9 6 30 2 79 12 14 2 68 16 7 1 9 79 12 2 79 7 6 2 1 73 79 85 86 79 33 17 10
              10 71 6 10 71 7 13 20 79 11 16 1 68 11 14 10 3 79 5 9 11 68 6 2 11 9 8 68 15 6 23 71 0 19 9 79 20 2
              0 20 11 10 72 71 7 1 71 24 5 20 79 10 8 27 68 6 12 7 2 31 16 2 11 74 71 94 86 71 45 17 19 79 16 8 79
              5 11 3 68 16 7 11 71 13 1 11 6 1 17 10 0 71 7 13 10 79 5 9 11 68 6 12 7 2 31 16 2 11 68 15 6 9 75 79
              12 2 79 3 6 25 1 71 27 12 2 79 22 14 8 12 19 79 16 8 79 6 2 12 11 10 10 68 4 7 13 11 11 22 2 1 68 8
              9 68 32 0 0 73 79 85 84 79 48 15 10 29 71 14 22 2 79 22 2 13 11 21 1 69 71 59 12 14 28 68 14 28 68 9
              0 16 71 14 68 23 7 29 20 6 7 6 3 68 5 6 22 19 7 68 21 10 23 18 3 16 14 1 3 71 9 22 8 2 68 15 26 9 6
              1 68 23 14 23 20 6 11 9 79 11 21 79 20 11 14 10 75 79 16 15 6 23 71 29 1 5 6 22 19 7 68 4 0 9 2 28
              68 1 29 11 10 79 35 8 11 74 86 91 68 52 0 68 19 7 1 71 56 11 21 11 68 5 10 7 6 2 1 71 7 17 10 14 10
              71 14 10 3 79 8 14 25 1 3 79 12 2 29 1 71 0 10 71 10 5 21 27 12 71 14 9 8 1 3 71 26 23 73 79 44 2 79
              19 6 28 68 1 26 8 11 79 11 1 79 17 9 9 5 14 3 13 9 8 68 11 0 18 2 79 5 9 11 68 1 14 13 19 7 2 18 3 10
              2 28 23 73 79 37 9 11 68 16 10 68 15 14 18 2 79 23 2 10 10 71 7 13 20 79 3 11 0 22 30 67 68 19 7 1
              71 8 8 8 29 29 71 0 2 71 27 12 2 79 11 9 3 29 71 60 11 9 79 11 1 79 16 15 10 68 33 14 16 15 10 22 73]]
    (eulerize data)))
	(ns euler-59)

	(defn decryptions [data]
	(let [chrs (range (int \a) (inc (int \z)))]
	(for [a chrs b chrs c chrs]
	(let [k (cycle [a b c])]
	(map (fn [a b] (bit-xor a b)) data k)))))

	; Doesn't take much to validate english!
	(defn possibly-valid? [str]
	(re-find #"(?i: or )" str))

	(defn eulerize [data]
	(->> data
	decryptions
	; this next step is a massive speedup. Each possible decryption is a
	; lazy-seq, so if I can filter it out without fully executing it,
	; I can save a lot of work. On my machine, moving the following 3 lines from
	; inside decryptions to here improved the speed to solution from 2100ms to 33ms.
	(filter (fn [stream] (not-any? #(< (int \z) %) stream)))
	(map #(map char %))
	(map clojure.string/join)
	(filter possibly-valid?)
	first
	(map int)
	(apply +)))


	(defn run []
	; too lazy to bather with reading the csv
	(let [data [79 59 12 2 79 35 8 28 20 2 3 68 8 9 68 45 0 12 9 67 68 4 7 5 23 27 1 21 79 85 78 79 85 71 38 10
	71 27 12 2 79 6 2 8 13 9 1 13 9 8 68 19 7 1 71 56 11 21 11 68 6 3 22 2 14 0 30 79 1 31 6 23 19 10 0
	73 79 44 2 79 19 6 28 68 16 6 16 15 79 35 8 11 72 71 14 10 3 79 12 2 79 19 6 28 68 32 0 0 73 79 86
	71 39 1 71 24 5 20 79 13 9 79 16 15 10 68 5 10 3 14 1 10 14 1 3 71 24 13 19 7 68 32 0 0 73 79 87 71
	39 1 71 12 22 2 14 16 2 11 68 2 25 1 21 22 16 15 6 10 0 79 16 15 10 22 2 79 13 20 65 68 41 0 16 15 6
	10 0 79 1 31 6 23 19 28 68 19 7 5 19 79 12 2 79 0 14 11 10 64 27 68 10 14 15 2 65 68 83 79 40 14 9
	1 71 6 16 20 10 8 1 79 19 6 28 68 14 1 68 15 6 9 75 79 5 9 11 68 19 7 13 20 79 8 14 9 1 71 8 13 17
	10 23 71 3 13 0 7 16 71 27 11 71 10 18 2 29 29 8 1 1 73 79 81 71 59 12 2 79 8 14 8 12 19 79 23 15 6
	10 2 28 68 19 7 22 8 26 3 15 79 16 15 10 68 3 14 22 12 1 1 20 28 72 71 14 10 3 79 16 15 10 68 3 14 22
	12 1 1 20 28 68 4 14 10 71 1 1 17 10 22 71 10 28 19 6 10 0 26 13 20 7 68 14 27 74 71 89 68 32 0 0 71
	28 1 9 27 68 45 0 12 9 79 16 15 10 68 37 14 20 19 6 23 19 79 83 71 27 11 71 27 1 11 3 68 2 25 1 21
	22 11 9 10 68 6 13 11 18 27 68 19 7 1 71 3 13 0 7 16 71 28 11 71 27 12 6 27 68 2 25 1 21 22 11 9 10
	68 10 6 3 15 27 68 5 10 8 14 10 18 2 79 6 2 12 5 18 28 1 71 0 2 71 7 13 20 79 16 2 28 16 14 2 11 9
	22 74 71 87 68 45 0 12 9 79 12 14 2 23 2 3 2 71 24 5 20 79 10 8 27 68 19 7 1 71 3 13 0 7 16 92 79 12
	2 79 19 6 28 68 8 1 8 30 79 5 71 24 13 19 1 1 20 28 68 19 0 68 19 7 1 71 3 13 0 7 16 73 79 93 71 59
	12 2 79 11 9 10 68 16 7 11 71 6 23 71 27 12 2 79 16 21 26 1 71 3 13 0 7 16 75 79 19 15 0 68 0 6 18 2
	28 68 11 6 3 15 27 68 19 0 68 2 25 1 21 22 11 9 10 72 71 24 5 20 79 3 8 6 10 0 79 16 8 79 7 8 2 1 71
	6 10 19 0 68 19 7 1 71 24 11 21 3 0 73 79 85 87 79 38 18 27 68 6 3 16 15 0 17 0 7 68 19 7 1 71 24 11
	21 3 0 71 24 5 20 79 9 6 11 1 71 27 12 21 0 17 0 7 68 15 6 9 75 79 16 15 10 68 16 0 22 11 11 68 3 6
	0 9 72 16 71 29 1 4 0 3 9 6 30 2 79 12 14 2 68 16 7 1 9 79 12 2 79 7 6 2 1 73 79 85 86 79 33 17 10
	10 71 6 10 71 7 13 20 79 11 16 1 68 11 14 10 3 79 5 9 11 68 6 2 11 9 8 68 15 6 23 71 0 19 9 79 20 2
	0 20 11 10 72 71 7 1 71 24 5 20 79 10 8 27 68 6 12 7 2 31 16 2 11 74 71 94 86 71 45 17 19 79 16 8 79
	5 11 3 68 16 7 11 71 13 1 11 6 1 17 10 0 71 7 13 10 79 5 9 11 68 6 12 7 2 31 16 2 11 68 15 6 9 75 79
	12 2 79 3 6 25 1 71 27 12 2 79 22 14 8 12 19 79 16 8 79 6 2 12 11 10 10 68 4 7 13 11 11 22 2 1 68 8
	9 68 32 0 0 73 79 85 84 79 48 15 10 29 71 14 22 2 79 22 2 13 11 21 1 69 71 59 12 14 28 68 14 28 68 9
	0 16 71 14 68 23 7 29 20 6 7 6 3 68 5 6 22 19 7 68 21 10 23 18 3 16 14 1 3 71 9 22 8 2 68 15 26 9 6
	1 68 23 14 23 20 6 11 9 79 11 21 79 20 11 14 10 75 79 16 15 6 23 71 29 1 5 6 22 19 7 68 4 0 9 2 28
	68 1 29 11 10 79 35 8 11 74 86 91 68 52 0 68 19 7 1 71 56 11 21 11 68 5 10 7 6 2 1 71 7 17 10 14 10
	71 14 10 3 79 8 14 25 1 3 79 12 2 29 1 71 0 10 71 10 5 21 27 12 71 14 9 8 1 3 71 26 23 73 79 44 2 79
	19 6 28 68 1 26 8 11 79 11 1 79 17 9 9 5 14 3 13 9 8 68 11 0 18 2 79 5 9 11 68 1 14 13 19 7 2 18 3 10
	2 28 23 73 79 37 9 11 68 16 10 68 15 14 18 2 79 23 2 10 10 71 7 13 20 79 3 11 0 22 30 67 68 19 7 1
	71 8 8 8 29 29 71 0 2 71 27 12 2 79 11 9 3 29 71 60 11 9 79 11 1 79 16 15 10 68 33 14 16 15 10 22 73]]
	(eulerize data)))