Data commit

Task/Run-length-encoding/F-Sharp/run-length-encoding.fs

@@ -0,0 +1,18 @@
+open System
+open System.Text.RegularExpressions
+
+let encode data =
+    // encodeData : seq<'T> -> seq<int * 'T> i.e. Takes a sequence of 'T types and return a sequence of tuples containing the run length and an instance of 'T.
+    let rec encodeData input =
+        seq { if not (Seq.isEmpty input) then
+                 let head = Seq.head input
+                 let runLength = Seq.length (Seq.takeWhile ((=) head) input)
+                 yield runLength, head
+                 yield! encodeData (Seq.skip runLength input) }
+
+    encodeData data |> Seq.fold(fun acc (len, d) -> acc + len.ToString() + d.ToString()) ""
+
+let decode str =
+    [ for m in Regex.Matches(str, "(\d+)(.)") -> m ]
+    |> List.map (fun m -> Int32.Parse(m.Groups.[1].Value), m.Groups.[2].Value)
+    |> List.fold (fun acc (len, s) -> acc + String.replicate len s) ""