Data commit

Task/Caesar-cipher/Scala/caesar-cipher-1.scala

@@ -0,0 +1,12 @@
+object Caesar {
+  private val alphaU='A' to 'Z'
+  private val alphaL='a' to 'z'
+
+  def encode(text:String, key:Int)=text.map{
+    case c if alphaU.contains(c) => rot(alphaU, c, key)
+    case c if alphaL.contains(c) => rot(alphaL, c, key)
+    case c => c
+  }
+  def decode(text:String, key:Int)=encode(text,-key)
+  private def rot(a:IndexedSeq[Char], c:Char, key:Int)=a((c-a.head+key+a.size)%a.size)
+}

Task/Caesar-cipher/Scala/caesar-cipher-2.scala

@@ -0,0 +1,5 @@
+val text="The five boxing wizards jump quickly"
+println("Plaintext  => " + text)
+val encoded=Caesar.encode(text, 3)
+println("Ciphertext => " + encoded)
+println("Decrypted  => " + Caesar.decode(encoded, 3))

Task/Caesar-cipher/Scala/caesar-cipher-3.scala

@@ -0,0 +1,12 @@
+class Caeser(val key: Int) {
+  @annotation.tailrec
+  private def rotate(p: Int, s: IndexedSeq[Char]): IndexedSeq[Char] = if (p < 0) rotate(s.length + p, s) else s.drop(p) ++ s.take(p)
+
+  val uc = 'A' to 'Z'
+  val lc = 'a' to 'z'
+  val as = uc ++ lc
+  val bs = rotate(key, uc) ++ rotate(key, lc)
+
+  def encode(c: Char) = if (as.contains(c)) bs(as.indexOf(c)) else c
+  def decode(c: Char) = if (bs.contains(c)) as(bs.indexOf(c)) else c
+}

Task/Caesar-cipher/Scala/caesar-cipher-4.scala

@@ -0,0 +1,6 @@
+val text = "The five boxing wizards jump quickly"
+val myCaeser = new Caeser(3)
+val encoded = text.map(c => myCaeser.encode(c))
+println("Plaintext => " + text)
+println("Ciphertext => " + encoded)
+println("Decrypted => " + encoded.map(c => myCaeser.decode(c)))