Data commit

Task/Vigen-re-cipher/CoffeeScript/vigen-re-cipher.coffee

@@ -0,0 +1,35 @@
+# Simple helper since charCodeAt is quite long to write.
+code = (char) -> char.charCodeAt()
+
+encrypt = (text, key) ->
+	res = []
+	j = 0
+	
+	for c in text.toUpperCase()
+		continue if c < 'A' or c > 'Z'
+		
+		res.push ((code c) + (code key[j]) - 130) % 26 + 65
+		j = ++j % key.length
+	
+	String.fromCharCode res...
+
+decrypt = (text, key) ->
+	res = []
+	j = 0
+	
+	for c in text.toUpperCase()
+		continue if c < 'A' or c > 'Z'
+		
+		res.push ((code c) - (code key[j]) + 26) % 26 + 65
+		j = ++j % key.length
+	
+	String.fromCharCode res...
+
+# Trying it out
+key       = "VIGENERECIPHER"
+original  = "Beware the Jabberwock, my son! The jaws that bite, the claws that catch!"
+encrypted = encrypt original, key
+
+console.log "Original  : #{original}"
+console.log "Encrypted : #{encrypted}"
+console.log "Decrypted : #{decrypt encrypted, key}"