Data commit

Task/Look-and-say-sequence/Clojure/look-and-say-sequence-1.clj

@@ -0,0 +1,16 @@
+(defn digits-seq
+  "Returns a seq of the digits of a number (L->R)."
+  [n]
+  (loop [digits (), number n]
+    (if (zero? number) (seq digits)
+        (recur (cons (mod number 10) digits)
+               (quot number 10)))))
+
+(defn join-digits
+  "Converts a digits-seq back in to a number."
+  [ds]
+  (reduce (fn [n d] (+ (* 10 n) d)) ds))
+
+(defn look-and-say [n]
+  (->> n digits-seq (partition-by identity)
+       (mapcat (juxt count first)) join-digits))

Task/Look-and-say-sequence/Clojure/look-and-say-sequence-2.clj

@@ -0,0 +1,2 @@
+user> (take 8 (iterate look-and-say 1))
+(1 11 21 1211 111221 312211 13112221 1113213211)

Task/Look-and-say-sequence/Clojure/look-and-say-sequence-3.clj

@@ -0,0 +1,7 @@
+(defn look-and-say
+  [n]
+  (->> (re-seq #"(.)\1*" n)
+       (mapcat (comp (juxt count first) first))
+       (apply str)))
+
+(take 12 (iterate look-and-say "1"))

Task/Look-and-say-sequence/Clojure/look-and-say-sequence-4.clj

@@ -0,0 +1,12 @@
+("1"
+ "11"
+ "21"
+ "1211"
+ "111221"
+ "312211"
+ "13112221"
+ "1113213211"
+ "31131211131221"
+ "13211311123113112211"
+ "11131221133112132113212221"
+ "3113112221232112111312211312113211")