tasks a-s

Task/Run-length-encoding/Scala/run-length-encoding-1.scala

@@ -0,0 +1,13 @@
+def encode(s: String) = (1 until s.size).foldLeft((1, s(0), new StringBuilder)) {
+  case ((len, c, sb), index) if c != s(index) => sb.append(len); sb.append(c); (1, s(index), sb)
+  case ((len, c, sb), _) => (len + 1, c, sb)
+} match {
+  case (len, c, sb) => sb.append(len); sb.append(c); sb.toString
+}
+
+def decode(s: String) = {
+  val sb = new StringBuilder
+  val Code = """(\d+)([A-Z])""".r
+  for (Code(len, c) <- Code findAllIn s) sb.append(c * len.toInt)
+  sb.toString
+}

Task/Run-length-encoding/Scala/run-length-encoding-2.scala

@@ -0,0 +1,4 @@
+def encode(s:String) = {
+  s.foldLeft((0,s(0),""))( (t,c) => t match {case (i,p,s) => if (p==c) (i+1,p,s) else (1,c,s+i+p)})
+    match {case (i,p,s) => s+i+p}
+}