June 2018 Update

Task/Caesar-cipher/Clojure/caesar-cipher-1.clj

@@ -0,0 +1,23 @@
+(defn encrypt-character [offset c]
+  (if (Character/isLetter c)
+    (let [v (int c)
+          base (if (>= v (int \a))
+                 (int \a)
+                 (int \A))
+          offset (mod offset 26)] ;works with negative offsets too!
+      (char (+ (mod (+ (- v base) offset) 26)
+               base)))
+    c))
+
+(defn encrypt [offset text]
+  (apply str (map #(encrypt-character offset %) text)))
+
+(defn decrypt [offset text]
+  (encrypt (- 26 offset) text))
+
+
+(let [text "The Quick Brown Fox Jumps Over The Lazy Dog."
+      enc (encrypt -1 text)]
+  (print "Original text:" text "\n")
+  (print "Encryption:" enc "\n")
+  (print "Decryption:" (decrypt -1 enc) "\n"))