tasks a-s

Task/Run-length-encoding/Tcl/run-length-encoding-1.tcl

@@ -0,0 +1,15 @@
+proc encode {string} {
+    set encoding {}
+    # use a regular expression to match runs of one character
+    foreach {run -} [regexp -all -inline {(.)\1+|.} $string] {
+        lappend encoding [string length $run] [string index $run 0]
+    }
+    return $encoding
+}
+
+proc decode {encoding} {
+    foreach {count char} $encoding  {
+        append decoded [string repeat $char $count]
+    }
+    return $decoded
+}

Task/Run-length-encoding/Tcl/run-length-encoding-2.tcl

@@ -0,0 +1,6 @@
+set str "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"
+set enc [encode $str] ;# ==> {12 W 1 B 12 W 3 B 24 W 1 B 14 W}
+set dec [decode $enc]
+if {$str eq $dec} {
+    puts "success"
+}