Data commit

Task/Vampire-number/Clojure/vampire-number.clj

@@ -0,0 +1,23 @@
+(defn factor-pairs [n]
+  (for [x (range 2 (Math/sqrt n))
+        :when (zero? (mod n x))]
+    [x (quot n x)]))
+
+(defn fangs [n]
+  (let [dlen (comp count str)
+        half (/ (dlen n) 2)
+        halves? #(apply = (cons half (map dlen %)))
+        digits  #(sort (apply str %))]
+    (filter #(and (halves? %)
+                  (= (sort (str n)) (digits %)))
+            (factor-pairs n))))
+
+(defn vampiric? [n]
+  (let [fangs (fangs n)]
+    (if (empty? fangs) nil [n fangs])))
+
+(doseq [n (take 25 (keep vampiric? (range)))]
+  (prn n))
+
+(doseq [n [16758243290880, 24959017348650, 14593825548650]]
+  (println (or (vampiric? n) (str n " is not vampiric."))))